結果
問題 | No.1553 Lovely City |
ユーザー |
![]() |
提出日時 | 2021-06-19 17:37:40 |
言語 | C++14 (gcc 13.3.0 + boost 1.87.0) |
結果 |
AC
|
実行時間 | 126 ms / 2,000 ms |
コード長 | 2,659 bytes |
コンパイル時間 | 1,136 ms |
コンパイル使用メモリ | 102,200 KB |
実行使用メモリ | 24,464 KB |
最終ジャッジ日時 | 2024-06-22 22:12:15 |
合計ジャッジ時間 | 7,198 ms |
ジャッジサーバーID (参考情報) |
judge3 / judge4 |
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ファイルパターン | 結果 |
---|---|
sample | AC * 2 |
other | AC * 26 |
ソースコード
/* -*- coding: utf-8 -*-** 1553.cc: No.1553 Lovely City - yukicoder*/#include<cstdio>#include<cstdlib>#include<cstring>#include<cmath>#include<iostream>#include<string>#include<vector>#include<map>#include<set>#include<stack>#include<list>#include<queue>#include<deque>#include<algorithm>#include<numeric>#include<utility>#include<complex>#include<functional>using namespace std;/* constant */const int MAX_N = 200000;/* typedef */typedef vector<int> vi;typedef queue<int> qi;typedef pair<int,int> pii;struct UFT {int links[MAX_N], ranks[MAX_N], sizes[MAX_N];UFT() {}void init(int n) {for (int i = 0; i < n; i++) links[i] = i, ranks[i] = sizes[i] = 1;}int root(int i) {int i0 = i;while (links[i0] != i0) i0 = links[i0];return (links[i] = i0);}int rank(int i) { return ranks[root(i)]; }int size(int i) { return sizes[root(i)]; }bool same(int i, int j) { return root(i) == root(j); }int merge(int i0, int i1) {int r0 = root(i0), r1 = root(i1), mr;if (r0 == r1) return r0;if (ranks[r0] == ranks[r1]) {links[r1] = r0;sizes[r0] += sizes[r1];ranks[r0]++;mr = r0;}else if (ranks[r0] > ranks[r1]) {links[r1] = r0;sizes[r0] += sizes[r1];mr = r0;}else {links[r0] = r1;sizes[r1] += sizes[r0];mr = r1;}return mr;}};/* global variables */vi nbrs[MAX_N], vs[MAX_N];int pns[MAX_N], ids[MAX_N], sv[MAX_N];UFT uft;pii es[MAX_N];/* subroutines *//* main */int main() {int n, m;scanf("%d%d", &n, &m);uft.init(n);for (int i = 0; i < m; i++) {int u, v;scanf("%d%d", &u, &v);u--, v--;nbrs[u].push_back(v);pns[v]++;uft.merge(u, v);}memset(ids, -1, sizeof(ids));int gn = 0;for (int i = 0; i < n; i++) {int ri = uft.root(i);if (ids[ri] < 0) ids[ri] = gn++;vs[ids[ri]].push_back(i);}//printf("gn=%d\n", gn);int k = 0;for (int gi = 0; gi < gn; gi++) {vi &vg = vs[gi];qi q;for (auto u: vg)if (pns[u] == 0) q.push(u);int sn = 0;while (! q.empty()) {int u = q.front(); q.pop();sv[sn++] = u;for (auto v: nbrs[u])if (--pns[v] == 0) q.push(v);}if (sn == vg.size())for (int i = 0; i + 1 < sn; i++)es[k++] = pii(sv[i], sv[i + 1]);else {for (int i = 0; i + 1 < vg.size(); i++)es[k++] = pii(vg[i], vg[i + 1]);es[k++] = pii(vg[vg.size() - 1], vg[0]);}}printf("%d\n", k);for (int i = 0; i < k; i++)printf("%d %d\n", es[i].first + 1, es[i].second + 1);return 0;}