結果

問題 No.1424 Ultrapalindrome
コンテスト
ユーザー LayCurse
提出日時 2021-03-12 22:53:42
言語 C++17
(gcc 13.3.0 + boost 1.87.0)
結果
AC  
実行時間 10 ms / 2,000 ms
コード長 5,161 bytes
コンパイル時間 2,216 ms
コンパイル使用メモリ 211,440 KB
最終ジャッジ日時 2025-01-19 15:30:02
ジャッジサーバーID
（参考情報） 		judge3 / judge3
このコードへのチャレンジ
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ファイルパターン 結果
sample AC * 3
other AC * 29
権限があれば一括ダウンロードができます
コンパイルメッセージ
main.cpp: In function ‘int main()’:
main.cpp:229:11: warning: ‘FmcKpFmN’ may be used uninitialized [-Wmaybe-uninitialized]
  229 |   if(g.es[r] == 2){
      |           ^
main.cpp:209:7: note: ‘FmcKpFmN’ was declared here
  209 |   int FmcKpFmN;
      |       ^~~~~~~~

ソースコード

diff # 

#pragma GCC optimize ("Ofast")
#include<bits/stdc++.h>
using namespace std;
void*wmem;
char memarr[96000000];
template<class T> inline void walloc1d(T **arr, int x, void **mem = &wmem){
  static int skip[16] = {0, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1};
  (*mem) = (void*)( ((char*)(*mem)) + skip[((unsigned long long)(*mem)) & 15] );
  (*arr)=(T*)(*mem);
  (*mem)=((*arr)+x);
}
template<class T> inline void walloc1d(T **arr, int x1, int x2, void **mem = &wmem){
  walloc1d(arr, x2-x1, mem);
  (*arr) -= x1;
}
inline int my_getchar_unlocked(){
  static char buf[1048576];
  static int s = 1048576;
  static int e = 1048576;
  if(s == e && e == 1048576){
    e = fread_unlocked(buf, 1, 1048576, stdin);
    s = 0;
  }
  if(s == e){
    return EOF;
  }
  return buf[s++];
}
inline void rd(int &x){
  int k;
  int m=0;
  x=0;
  for(;;){
    k = my_getchar_unlocked();
    if(k=='-'){
      m=1;
      break;
    }
    if('0'<=k&&k<='9'){
      x=k-'0';
      break;
    }
  }
  for(;;){
    k = my_getchar_unlocked();
    if(k<'0'||k>'9'){
      break;
    }
    x=x*10+k-'0';
  }
  if(m){
    x=-x;
  }
}
struct MY_WRITER{
  char buf[1048576];
  int s;
  int e;
  MY_WRITER(){
    s = 0;
    e = 1048576;
  }
  ~MY_WRITER(){
    if(s){
      fwrite_unlocked(buf, 1, s, stdout);
    }
  }
}
;
MY_WRITER MY_WRITER_VAR;
void my_putchar_unlocked(int a){
  if(MY_WRITER_VAR.s == MY_WRITER_VAR.e){
    fwrite_unlocked(MY_WRITER_VAR.buf, 1, MY_WRITER_VAR.s, stdout);
    MY_WRITER_VAR.s = 0;
  }
  MY_WRITER_VAR.buf[MY_WRITER_VAR.s++] = a;
}
inline void wt_L(char a){
  my_putchar_unlocked(a);
}
inline void wt_L(const char c[]){
  int i=0;
  for(i=0;c[i]!='\0';i++){
    my_putchar_unlocked(c[i]);
  }
}
struct graph{
  int N;
  int*es;
  int**edge;
  void setEdge(int N__, int M, int A[], int B[], void **mem = &wmem){
    int i;
    N = N__;
    walloc1d(&es, N, mem);
    walloc1d(&edge, N, mem);
    for(i=(0);i<(N);i++){
      es[i] = 0;
    }
    for(i=(0);i<(M);i++){
      es[A[i]]++;
      es[B[i]]++;
    }
    for(i=(0);i<(N);i++){
      walloc1d(&edge[i], es[i], mem);
    }
    for(i=(0);i<(N);i++){
      es[i] = 0;
    }
    for(i=(0);i<(M);i++){
      edge[A[i]][es[A[i]]++] = B[i];
      edge[B[i]][es[B[i]]++] = A[i];
    }
  }
  void getDist(int root, int res[], void *mem = wmem){
    int i;
    int j;
    int k;
    int*q;
    int s;
    int z;
    walloc1d(&q, N, &mem);
    for(i=(0);i<(N);i++){
      res[i]=-1;
    }
    res[root]=0;
    s=0;
    z=1;
    q[0]=root;
    while(z){
      i=q[s++];
      z--;
      for(j=(0);j<(es[i]);j++){
        k=edge[i][j];
        if(res[k]>=0){
          continue;
        }
        res[k]=res[i]+1;
        q[s+z++]=k;
      }
    }
  }
  int getDist(int a, int b, void *mem = wmem){
    int i;
    int j;
    int k;
    int*q;
    int s;
    int z;
    int*d;
    if(a==b){
      return 0;
    }
    walloc1d(&d, N, &mem);
    walloc1d(&q, N, &mem);
    for(i=(0);i<(N);i++){
      d[i] = -1;
    }
    d[a] = 0;
    s = 0;
    z = 1;
    q[0] = a;
    while(z){
      i = q[s++];
      z--;
      for(j=(0);j<(es[i]);j++){
        k = edge[i][j];
        if(d[k] >= 0){
          continue;
        }
        d[k] = d[i] + 1;
        if(k==b){
          return d[k];
        }
        q[s+z++] = k;
      }
    }
    return -1;
  }
}
;
int N;
int A[100000];
int B[100000];
graph g;
int d[100000];
int main(){
  int i;
  wmem = memarr;
  int r;
  int lf = 0;
  int mx = -1;
  rd(N);
  {
    int Lj4PdHRW;
    for(Lj4PdHRW=(0);Lj4PdHRW<(N-1);Lj4PdHRW++){
      rd(A[Lj4PdHRW]);A[Lj4PdHRW] += (-1);
      rd(B[Lj4PdHRW]);B[Lj4PdHRW] += (-1);
    }
  }
  if(N <= 3){
    wt_L("Yes");
    wt_L('\n');
    return 0;
  }
  g.setEdge(N,N-1,A,B);
  int e98WHCEY;
  remove_reference<decltype(g.es[e98WHCEY])>::type cTE1_r3A;
  int RZTsC2BF = 0;
  int FmcKpFmN;
  if((0) > ((N)-1)){
    cTE1_r3A = 0;
  }
  else{
    for(e98WHCEY = 0; e98WHCEY <= (N)-1; e98WHCEY++){
      if(RZTsC2BF == 0){
        cTE1_r3A = g.es[e98WHCEY];
        FmcKpFmN = e98WHCEY;
        RZTsC2BF = 1;
        continue;
      }
      const auto xr20shxY = g.es[e98WHCEY];
      if(cTE1_r3A < xr20shxY){
        cTE1_r3A = xr20shxY;
        FmcKpFmN = e98WHCEY;
      }
    }
  }
  r =FmcKpFmN;
  if(g.es[r] == 2){
    wt_L("Yes");
    wt_L('\n');
    return 0;
  }
  g.getDist(r, d);
  for(i=(0);i<(N);i++){
    if(g.es[i]==1){
      lf++;
      if(mx == -1){
        mx = d[i];
      }
      if(mx != d[i]){
        wt_L("No");
        wt_L('\n');
        return 0;
      }
    }
  }
  if(lf != g.es[r]){
    wt_L("No");
    wt_L('\n');
    return 0;
  }
  wt_L("Yes");
  wt_L('\n');
  return 0;
}
// cLay version 20210227-1

// --- original code ---
// int N, A[1d5], B[];
// graph g;
// int d[];
// {
//   int r, lf = 0, mx = -1;
//   rd(N,(A--,B--)(N-1));
//   if(N <= 3) wt("Yes"), return 0;
// 
//   g.setEdge(N,N-1,A,B);
//   r = argmax[i,0,N](g.es[i]);
//   if(g.es[r] == 2) wt("Yes"), return 0;
//   
//   g.getDist(r, d);
//   rep(i,N) if(g.es[i]==1){
//     lf++;
//     if(mx == -1) mx = d[i];
//     if(mx != d[i]) wt("No"), return 0;
//   }
//   if(lf != g.es[r]) wt("No"), return 0;
// 
//   wt("Yes");
// }
0