結果
| 問題 | No.1976 Cut then Connect |
| ユーザー |
 uwi
|
| 提出日時 | 2022-06-10 22:12:17 |
| 言語 | Java (openjdk 23) |
| 結果 |
AC
|
| 実行時間 | 557 ms / 2,000 ms |
| コード長 | 21,484 bytes |
| コンパイル時間 | 5,632 ms |
| コンパイル使用メモリ | 94,148 KB |
| 実行使用メモリ | 65,464 KB |
| 最終ジャッジ日時 | 2024-11-24 12:14:12 |
| 合計ジャッジ時間 | 15,204 ms |
|
ジャッジサーバーID （参考情報） |
judge4 / judge1 |
（要ログイン）
| ファイルパターン | 結果 |
|---|---|
| sample | AC * 2 |
| other | AC * 31 |
ソースコード
package contest220610;import java.io.*;import java.util.ArrayDeque;import java.util.Arrays;import java.util.InputMismatchException;import java.util.Queue;import java.util.function.IntUnaryOperator;import java.util.function.LongUnaryOperator;public class F {InputStream is;FastWriter out;String INPUT = "";public void solve(){// 最大値じゃないのか…// 中心同士をつなぐとよさそう// even,evenで直径が同じなら、直径+1// even,oddでeven=odd-1, even=odd+1なら、直径+1// odd,oddで直径が同じなら直径+2// odd-odd=2ならmax+1int n = ni();int[] from = new int[n - 1];int[] to = new int[n - 1];for (int i = 0; i < n - 1; i++) {from[i] = ni() - 1;to[i] = ni() - 1;}int[][] g = packU(n, from, to);int[][] pars = parents(g, 0);int[] par = pars[0], ord = pars[1], dep = pars[2];lf = LCAFast2.build(g, 0);Datum[][] du = omnidirectionalTreeDP(g, par, ord);int ans = Integer.MAX_VALUE;for(int i = 1;i < n;i++){int x = du[0][i].diam;int y = du[1][i].diam;if(x > y){int d = x; x = y; y = d;}if(x % 2 == 0 && y % 2 == 0){ans = Math.min(ans, x == y ? y + 1 : y);}else if(x % 2 == 1 && y % 2 == 1){if(x == y){ans = Math.min(ans, y+2);}else if(y == x + 2){ans = Math.min(ans, y+1);}else{ans = Math.min(ans, y);}}else{if(y == x + 1){ans = Math.min(ans, y+1);}else{ans = Math.min(ans, y);}}}out.println(ans);}public static class Datum {int arg1, arg2;int diam;public Datum() {}public Datum(int cur) {arg1 = arg2 = cur;diam = 0;}@Overridepublic String toString() {return "Datum{" +"arg1=" + arg1 +", arg2=" + arg2 +", diam=" + diam +'}';}}public static Datum zero = new Datum();public static LCAFast2 lf;public static Datum merge(Datum a, Datum b) {Datum ret = new Datum();int d = -1;if(a.diam > d){d = a.diam; ret.arg1 = a.arg1; ret.arg2 = a.arg2;}if(b.diam > d){d = b.diam; ret.arg1 = b.arg1; ret.arg2 = b.arg2;}for(int u : new int[]{a.arg1, a.arg2}){for(int v : new int[]{b.arg1, b.arg2}){int td = lf.d(u, v);if(td > d){d = td; ret.arg1 = u; ret.arg2 = v;}}}ret.diam = d;return ret;}public static Datum promote(Datum d, int... e) {return merge(d, new Datum(e[0]));}public static Datum[][] omnidirectionalTreeDP(int[][] g, int[] par, int[] ord) {int n = g.length;int root = ord[0];Datum[] dp = new Datum[n];// upfor (int i = n - 1; i >= 0; i--) {int cur = ord[i];Datum ldp = new Datum(cur);for (int e : g[cur]) {if (par[cur] == e) continue;ldp = merge(ldp, promote(dp[e], e));}dp[cur] = ldp;}// downDatum[] prefix = new Datum[n + 1];Datum[] fall = new Datum[n];Datum[] down = new Datum[n];fall[root] = zero;for (int i = 0; i < n; i++) {int cur = ord[i];prefix[0] = zero;Datum suffix = merge(new Datum(cur), fall[cur]);for (int j = 0; j < g[cur].length; j++) {int e = g[cur][j];prefix[j + 1] = par[cur] == e ? prefix[j] : merge(prefix[j], promote(dp[e], e));}for (int j = 0; j < g[cur].length; j++) {int e = g[cur][g[cur].length - 1 - j];if (par[cur] != e) {down[e] = merge(prefix[g[cur].length - 1 - j], suffix);fall[e] = promote(down[e], e);}suffix = par[cur] == e ? suffix : merge(suffix, promote(dp[e], e));}}return new Datum[][]{dp, down};}public static class LCAFast2 {public int n, h;public int[][] bigst;public int[][] bigind;public long[][] smallb;public int[] vs, first, deps;public int lca(int a, int b) {return vs[rmqpos(Math.min(first[a], first[b]), Math.max(first[a], first[b]))];}public int pointOnPath(int a, int b, int dfroma) {int lca = lca(a, b);if (dfroma <= dep(a) - dep(lca)) {return anc(a, dfroma);}int dfromb = dep(b) - dep(lca) - (dfroma - (dep(a) - dep(lca)));if (dfromb < 0) return -1;return anc(b, dfromb);}public int anc(int a, int d) {int da = dep(a);if (da < d) return -1;int danc = da - d;int low = 0, high = first[a] + 1;while (high - low > 1) {int h = high + low >> 1;if (rmqval(h, first[a]) <= danc) {low = h;} else {high = h;}}return vs[low];}public int d(int a, int b) {return dep(a) + dep(b) - 2 * rmqval(Math.min(first[a], first[b]), Math.max(first[a], first[b]));}public int dep(int x) {return deps[first[x]];}public int rmqpos(int l, int r) {if (l > r) return -1;int cl = l >>> 6;int cr = r >>> 6;if (cl == cr) {return argmax(smallb[l & 63][cl], r - l + 1) + l;} else {int min = deps[l] - max(smallb[l & 63][cl], 63 - (l & 63) + 1);int pos = argmax(smallb[l & 63][cl], 63 - (l & 63) + 1) + l;{int can = deps[r >>> 6 << 6] - max(smallb[0][cr], (r & 63) - 0 + 1);if (can < min) {min = can;pos = argmax(smallb[0][cr], (r & 63) - 0 + 1) + (r >>> 6 << 6);}}if (cl + 1 <= cr - 1) {int len = (cr - 1) - (cl + 1) + 1;int h = 31 - Integer.numberOfLeadingZeros(len);{int can = bigst[h][cl + 1];if (can < min) {min = can;pos = bigind[h][cl + 1];}}{int can = bigst[h][cr - 1 - (1 << h) + 1];if (can < min) {min = can;pos = bigind[h][cr - 1 - (1 << h) + 1];}}}return pos;}}public int rmqval(int l, int r) {if (l > r) return -1;int cl = l >>> 6;int cr = r >>> 6;if (cl == cr) {return deps[l] - max(smallb[l & 63][cl], r - l + 1);} else {int min = deps[l] - max(smallb[l & 63][cl], 63 - (l & 63) + 1);min = Math.min(min, deps[r >>> 6 << 6] - max(smallb[0][cr], (r & 63) - 0 + 1));if (cl + 1 <= cr - 1) {int len = (cr - 1) - (cl + 1) + 1;int h = 31 - Integer.numberOfLeadingZeros(len);min = Math.min(min, bigst[h][cl + 1]);min = Math.min(min, bigst[h][cr - 1 - (1 << h) + 1]);}return min;}}public static LCAFast2 build(int[][] g, int root) {LCAFast2 ret = new LCAFast2();int[][] et = eulerTour(g, root);int[] vs = et[0], deps = et[1], first = et[2];ret.vs = vs;ret.first = first;ret.deps = deps;int n = deps.length;int u = n + 63 >>> 6;int h = 31 - Integer.numberOfLeadingZeros(u) + 1;int[][] bigst = new int[h][];int[][] bigind = new int[h][];int[] cup = new int[u];int[] cupind = new int[u];Arrays.fill(cup, Integer.MAX_VALUE);for (int i = 0; i < n; i++) {if (deps[i] < cup[i >>> 6]) {cup[i >>> 6] = deps[i];cupind[i >>> 6] = i;}}bigst[0] = cup;bigind[0] = cupind;for (int i = 1; i < h; i++) {bigst[i] = new int[u - (1 << i) + 1];bigind[i] = new int[u - (1 << i) + 1];for (int j = 0; j + (1 << i) <= u; j++) {if (bigst[i - 1][j] < bigst[i - 1][j + (1 << i - 1)]) {bigst[i][j] = bigst[i - 1][j];bigind[i][j] = bigind[i - 1][j];} else {bigst[i][j] = bigst[i - 1][j + (1 << i - 1)];bigind[i][j] = bigind[i - 1][j + (1 << i - 1)];}}}long[][] smallb = new long[64][u];for (int i = 0; i < u; i++) {long x = 0;for (int j = 0; j < 63 && (i << 6 | j + 1) < n; j++) {if (deps[i << 6 | j] > deps[i << 6 | j + 1]) {x |= 1L << j;}}long val = 0;for (int j = 63; j >= 0; j--) {val <<= 1;if (x << ~j < 0) {val |= 1L;} else {val &= val - 1;}smallb[j][i] = val;}//// for(int j = 0;j < 64;j++){// smallb[j][i] = make(x>>>j);// }}ret.n = n;ret.h = h;ret.bigst = bigst;ret.bigind = bigind;ret.smallb = smallb;return ret;}public static int[][] eulerTour(int[][] g, int root) {int n = g.length;int[] vs = new int[2 * n - 1];int[] deps = new int[2 * n - 1];int[] first = new int[n];Arrays.fill(first, -1);int p = 0;int[] stack = new int[n];int[] inds = new int[n];int sp = 0;stack[sp++] = root;outer:while (sp > 0) {int cur = stack[sp - 1], ind = inds[sp - 1];vs[p] = cur;deps[p] = sp - 1;if (first[cur] == -1) first[cur] = p;p++;while (ind < g[cur].length) {int nex = g[cur][ind++];if (first[nex] == -1) {inds[sp - 1] = ind;stack[sp] = nex;inds[sp] = 0;sp++;continue outer;}}inds[sp - 1] = ind;if (ind == g[cur].length) sp--;}return new int[][]{vs, deps, first};}// TinyRMQpublic static long make(long x) {int h = 0;int max = 0;long ret = 0;for (int i = 0; i < 64; i++) {if (x << ~i < 0) {h++;} else {h--;}if (h > max) {max = h;ret |= 1L << i;}}return ret;}public static int max(long x, int r) {assert r > 0;return Long.bitCount(x & (1L << r - 1) - 1);}public static int argmax(long x, int r) {assert r > 0;return 64 - Long.numberOfLeadingZeros(x & (1L << r - 1) - 1);}}public static int[][] parents(int[][] g, int root) {int n = g.length;int[] par = new int[n];Arrays.fill(par, -1);int[] depth = new int[n];depth[0] = 0;int[] q = new int[n];q[0] = root;for (int p = 0, r = 1; p < r; p++) {int cur = q[p];for (int nex : g[cur]) {if (par[cur] != nex) {q[r++] = nex;par[nex] = cur;depth[nex] = depth[cur] + 1;}}}return new int[][]{par, q, depth};}public static int[][] packU(int n, int[] from, int[] to) {return packU(n, from, to, from.length);}public static int[][] packU(int n, int[] from, int[] to, int sup) {int[][] g = new int[n][];int[] p = new int[n];for (int i = 0; i < sup; i++) p[from[i]]++;for (int i = 0; i < sup; i++) p[to[i]]++;for (int i = 0; i < n; i++) g[i] = new int[p[i]];for (int i = 0; i < sup; i++) {g[from[i]][--p[from[i]]] = to[i];g[to[i]][--p[to[i]]] = from[i];}return g;}public static void main(String[] args) {new F().run();}public void run(){long S = System.currentTimeMillis();is = INPUT.isEmpty() ? System.in : new ByteArrayInputStream(INPUT.getBytes());out = new FastWriter(System.out);solve();out.flush();long G = System.currentTimeMillis();tr(G-S+"ms");// Thread t = new Thread(null, null, "~", Runtime.getRuntime().maxMemory()){// @Override// public void run() {// long s = System.currentTimeMillis();// solve();// out.flush();// if(!INPUT.isEmpty())tr(System.currentTimeMillis()-s+"ms");// }// };// t.start();// t.join();}private boolean eof(){if(lenbuf == -1)return true;int lptr = ptrbuf;while(lptr < lenbuf)if(!isSpaceChar(inbuf[lptr++]))return false;try {is.mark(1000);while(true){int b = is.read();if(b == -1){is.reset();return true;}else if(!isSpaceChar(b)){is.reset();return false;}}} catch (IOException e) {return true;}}private final byte[] inbuf = new byte[1024];public int lenbuf = 0, ptrbuf = 0;private int readByte(){if(lenbuf == -1)throw new InputMismatchException();if(ptrbuf >= lenbuf){ptrbuf = 0;try { lenbuf = is.read(inbuf); } catch (IOException e) { throw new InputMismatchException(); }if(lenbuf <= 0)return -1;}return inbuf[ptrbuf++];}private boolean isSpaceChar(int c) { return !(c >= 33 && c <= 126); }// private boolean isSpaceChar(int c) { return !(c >= 32 && c <= 126); }private int skip() { int b; while((b = readByte()) != -1 && isSpaceChar(b)); return b; }private double nd() { return Double.parseDouble(ns()); }private char nc() { return (char)skip(); }private String ns(){int b = skip();StringBuilder sb = new StringBuilder();while(!(isSpaceChar(b))){sb.appendCodePoint(b);b = readByte();}return sb.toString();}private char[] ns(int n){char[] buf = new char[n];int b = skip(), p = 0;while(p < n && !(isSpaceChar(b))){buf[p++] = (char)b;b = readByte();}return n == p ? buf : Arrays.copyOf(buf, p);}private char[][] nm(int n, int m){char[][] map = new char[n][];for(int i = 0;i < n;i++)map[i] = ns(m);return map;}private int[][] nmi(int n, int m){int[][] map = new int[n][];for(int i = 0;i < n;i++)map[i] = na(m);return map;}private int[] na(int n){int[] a = new int[n];for(int i = 0;i < n;i++)a[i] = ni();return a;}private long[] nal(int n){long[] a = new long[n];for(int i = 0;i < n;i++)a[i] = nl();return a;}private int ni(){int num = 0, b;boolean minus = false;while((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'));if(b == '-'){minus = true;b = readByte();}while(true){if(b >= '0' && b <= '9'){num = num * 10 + (b - '0');}else{return minus ? -num : num;}b = readByte();}}private long nl(){long num = 0;int b;boolean minus = false;while((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'));if(b == '-'){minus = true;b = readByte();}while(true){if(b >= '0' && b <= '9'){num = num * 10 + (b - '0');}else{return minus ? -num : num;}b = readByte();}}public static class FastWriter{private static final int BUF_SIZE = 1<<13;private final byte[] buf = new byte[BUF_SIZE];private final OutputStream out;private int ptr = 0;private FastWriter(){out = null;}public FastWriter(OutputStream os){this.out = os;}public FastWriter(String path){try {this.out = new FileOutputStream(path);} catch (FileNotFoundException e) {throw new RuntimeException("FastWriter");}}public FastWriter write(byte b){buf[ptr++] = b;if(ptr == BUF_SIZE)innerflush();return this;}public FastWriter write(char c){return write((byte)c);}public FastWriter write(char[] s){for(char c : s){buf[ptr++] = (byte)c;if(ptr == BUF_SIZE)innerflush();}return this;}public FastWriter write(String s){s.chars().forEach(c -> {buf[ptr++] = (byte)c;if(ptr == BUF_SIZE)innerflush();});return this;}private static int countDigits(int l) {if (l >= 1000000000) return 10;if (l >= 100000000) return 9;if (l >= 10000000) return 8;if (l >= 1000000) return 7;if (l >= 100000) return 6;if (l >= 10000) return 5;if (l >= 1000) return 4;if (l >= 100) return 3;if (l >= 10) return 2;return 1;}public FastWriter write(int x){if(x == Integer.MIN_VALUE){return write((long)x);}if(ptr + 12 >= BUF_SIZE)innerflush();if(x < 0){write((byte)'-');x = -x;}int d = countDigits(x);for(int i = ptr + d - 1;i >= ptr;i--){buf[i] = (byte)('0'+x%10);x /= 10;}ptr += d;return this;}private static int countDigits(long l) {if (l >= 1000000000000000000L) return 19;if (l >= 100000000000000000L) return 18;if (l >= 10000000000000000L) return 17;if (l >= 1000000000000000L) return 16;if (l >= 100000000000000L) return 15;if (l >= 10000000000000L) return 14;if (l >= 1000000000000L) return 13;if (l >= 100000000000L) return 12;if (l >= 10000000000L) return 11;if (l >= 1000000000L) return 10;if (l >= 100000000L) return 9;if (l >= 10000000L) return 8;if (l >= 1000000L) return 7;if (l >= 100000L) return 6;if (l >= 10000L) return 5;if (l >= 1000L) return 4;if (l >= 100L) return 3;if (l >= 10L) return 2;return 1;}public FastWriter write(long x){if(x == Long.MIN_VALUE){return write("" + x);}if(ptr + 21 >= BUF_SIZE)innerflush();if(x < 0){write((byte)'-');x = -x;}int d = countDigits(x);for(int i = ptr + d - 1;i >= ptr;i--){buf[i] = (byte)('0'+x%10);x /= 10;}ptr += d;return this;}public FastWriter write(double x, int precision){if(x < 0){write('-');x = -x;}x += Math.pow(10, -precision)/2;// if(x < 0){ x = 0; }write((long)x).write(".");x -= (long)x;for(int i = 0;i < precision;i++){x *= 10;write((char)('0'+(int)x));x -= (int)x;}return this;}public FastWriter writeln(char c){ return write(c).writeln(); }public FastWriter writeln(int x){ return write(x).writeln(); }public FastWriter writeln(long x){ return write(x).writeln(); }public FastWriter writeln(double x, int precision){ return write(x, precision).writeln(); }public FastWriter write(int... xs){boolean first = true;for(int x : xs) {if (!first) write(' ');first = false;write(x);}return this;}public FastWriter write(long... xs){boolean first = true;for(long x : xs) {if (!first) write(' ');first = false;write(x);}return this;}public FastWriter write(IntUnaryOperator f, int... xs){boolean first = true;for(int x : xs) {if (!first) write(' ');first = false;write(f.applyAsInt(x));}return this;}public FastWriter write(LongUnaryOperator f, long... xs){boolean first = true;for(long x : xs) {if (!first) write(' ');first = false;write(f.applyAsLong(x));}return this;}public FastWriter writeln(){return write((byte)'\n');}public FastWriter writeln(int... xs) { return write(xs).writeln(); }public FastWriter writeln(long... xs) { return write(xs).writeln(); }public FastWriter writeln(IntUnaryOperator f, int... xs) { return write(f, xs).writeln(); }public FastWriter writeln(LongUnaryOperator f, long... xs) { return write(f, xs).writeln(); }public FastWriter writeln(char[] line) { return write(line).writeln(); }public FastWriter writeln(char[]... map) { for(char[] line : map)write(line).writeln();return this; }public FastWriter writeln(String s) { return write(s).writeln(); }private void innerflush(){try {out.write(buf, 0, ptr);ptr = 0;} catch (IOException e) {throw new RuntimeException("innerflush");}}public void flush(){innerflush();try {out.flush();} catch (IOException e) {throw new RuntimeException("flush");}}public FastWriter print(byte b) { return write(b); }public FastWriter print(char c) { return write(c); }public FastWriter print(char[] s) { return write(s); }public FastWriter print(String s) { return write(s); }public FastWriter print(int x) { return write(x); }public FastWriter print(long x) { return write(x); }public FastWriter print(double x, int precision) { return write(x, precision); }public FastWriter println(char c){ return writeln(c); }public FastWriter println(int x){ return writeln(x); }public FastWriter println(long x){ return writeln(x); }public FastWriter println(double x, int precision){ return writeln(x, precision); }public FastWriter print(int... xs) { return write(xs); }public FastWriter print(long... xs) { return write(xs); }public FastWriter print(IntUnaryOperator f, int... xs) { return write(f, xs); }public FastWriter print(LongUnaryOperator f, long... xs) { return write(f, xs); }public FastWriter println(int... xs) { return writeln(xs); }public FastWriter println(long... xs) { return writeln(xs); }public FastWriter println(IntUnaryOperator f, int... xs) { return writeln(f, xs); }public FastWriter println(LongUnaryOperator f, long... xs) { return writeln(f, xs); }public FastWriter println(char[] line) { return writeln(line); }public FastWriter println(char[]... map) { return writeln(map); }public FastWriter println(String s) { return writeln(s); }public FastWriter println() { return writeln(); }}public static void trnz(int... o){for(int i = 0;i < o.length;i++)if(o[i] != 0)System.out.print(i+":"+o[i]+" ");System.out.println();}// print ids which are 1public static void trt(long... o){Queue<Integer> stands = new ArrayDeque<>();for(int i = 0;i < o.length;i++){for(long x = o[i];x != 0;x &= x-1)stands.add(i<<6|Long.numberOfTrailingZeros(x));}System.out.println(stands);}public static void tf(boolean... r){for(boolean x : r)System.out.print(x?'#':'.');System.out.println();}public static void tf(boolean[]... b){for(boolean[] r : b) {for(boolean x : r)System.out.print(x?'#':'.');System.out.println();}System.out.println();}public void tf(long[]... b){if(INPUT.length() != 0) {for (long[] r : b) {for (long x : r) {for (int i = 0; i < 64; i++) {System.out.print(x << ~i < 0 ? '#' : '.');}}System.out.println();}System.out.println();}}public void tf(long... b){if(INPUT.length() != 0) {for (long x : b) {for (int i = 0; i < 64; i++) {System.out.print(x << ~i < 0 ? '#' : '.');}}System.out.println();}}private void tr(Object... o) { if(INPUT.length() != 0)System.out.println(Arrays.deepToString(o)); }}