oj.uz

Submission #19755

# Submission time Handle Problem Language Result Execution time Memory
19755 2016-02-25T05:17:26 Z xdoju 트리 (kriii4_X) C++14
100 / 100
 429 ms 11640 KB 
#include <stdio.h>
#include <map>
#include <utility>
using namespace std;

const int MOD = 1000000007;

map<int, int> par;
map<int, int> cnt;

int getroot(int x){
  if(par.find(x) == par.end()) par[x] = x;
  if(par[x] == x) return x;

  return (par[x] = getroot(par[x]));
}

int mul(int x, int y){ return (long long)x * y % MOD; }

int power(int x, int y){
  if(y == 0) return 1;

  int r = power(x, y / 2);
  r = mul(r, r);
  if(y % 2 == 1) r = mul(r, x);
  return r;
}

int main(){
  int N, M; scanf("%d%d", &N, &M);

  bool val = true;

  for(int i = 1; i <= M; i++){
    int x, y; scanf("%d%d", &x, &y);

    int px = getroot(x), py = getroot(y);
    if(px == py) val = false;
    else par[px] = py;
  }

  if(!val){ puts("0"); }
  else{
    for(pair<int, int> pp : par){
      int x = pp.first;
      cnt[getroot(x)]++;
    }

    int NN = N - (int)par.size() + (int)cnt.size();

    int ans = 1;

    if(NN != 1){
      for(pair<int, int> pp : cnt) ans = mul(ans, pp.second);
      ans = mul(ans, power(N, NN - 2));
    }

    printf("%d\n", ans);
  }
  return 0;
}

Subtask #1
9.0 / 9.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 1212 KB Output is correct
2 Correct 0 ms 1212 KB Output is correct
3 Correct 0 ms 1212 KB Output is correct
4 Correct 0 ms 1212 KB Output is correct
5 Correct 0 ms 1212 KB Output is correct
6 Correct 0 ms 1212 KB Output is correct
7 Correct 0 ms 1212 KB Output is correct
8 Correct 0 ms 1212 KB Output is correct
9 Correct 0 ms 1212 KB Output is correct
10 Correct 0 ms 1212 KB Output is correct
11 Correct 0 ms 1212 KB Output is correct
12 Correct 0 ms 1212 KB Output is correct
13 Correct 0 ms 1212 KB Output is correct
14 Correct 0 ms 1212 KB Output is correct
15 Correct 0 ms 1212 KB Output is correct
16 Correct 0 ms 1212 KB Output is correct
17 Correct 0 ms 1212 KB Output is correct
18 Correct 0 ms 1212 KB Output is correct
19 Correct 0 ms 1212 KB Output is correct
20 Correct 0 ms 1212 KB Output is correct
21 Correct 0 ms 1212 KB Output is correct
22 Correct 0 ms 1212 KB Output is correct
23 Correct 0 ms 1212 KB Output is correct
24 Correct 0 ms 1212 KB Output is correct
25 Correct 0 ms 1212 KB Output is correct
26 Correct 0 ms 1212 KB Output is correct
27 Correct 0 ms 1212 KB Output is correct
28 Correct 0 ms 1212 KB Output is correct
29 Correct 0 ms 1212 KB Output is correct
30 Correct 0 ms 1212 KB Output is correct

Subtask #2
91.0 / 91.0

# Verdict Execution time Memory Grader output
1 Correct 27 ms 1740 KB Output is correct
2 Correct 83 ms 2400 KB Output is correct
3 Correct 90 ms 2532 KB Output is correct
4 Correct 30 ms 1872 KB Output is correct
5 Correct 56 ms 2268 KB Output is correct
6 Correct 404 ms 10980 KB Output is correct
7 Correct 394 ms 11244 KB Output is correct
8 Correct 391 ms 4248 KB Output is correct
9 Correct 394 ms 11640 KB Output is correct
10 Correct 395 ms 9792 KB Output is correct
11 Correct 379 ms 5568 KB Output is correct
12 Correct 375 ms 5568 KB Output is correct
13 Correct 364 ms 5568 KB Output is correct
14 Correct 361 ms 5568 KB Output is correct
15 Correct 373 ms 5700 KB Output is correct
16 Correct 243 ms 5700 KB Output is correct
17 Correct 244 ms 5700 KB Output is correct
18 Correct 0 ms 1212 KB Output is correct
19 Correct 429 ms 5832 KB Output is correct
20 Correct 402 ms 5832 KB Output is correct
21 Correct 368 ms 5568 KB Output is correct
22 Correct 390 ms 5700 KB Output is correct
23 Correct 410 ms 5964 KB Output is correct
24 Correct 397 ms 5964 KB Output is correct
25 Correct 263 ms 7152 KB Output is correct
26 Correct 259 ms 7152 KB Output is correct
27 Correct 379 ms 9660 KB Output is correct
28 Correct 379 ms 9660 KB Output is correct
29 Correct 424 ms 5832 KB Output is correct
30 Correct 426 ms 5964 KB Output is correct