#include"bits/stdc++.h" using namespace std; #define LL long long #define REP(i, n) for(int (i)=0; (i)<(n); (i)++) #define PB push_back #define MP make_pair #define MOD 1000000007 int N, M; vector<pair<int, LL>> edge[300001]; int par[300001]; vector<pair<LL,int>> chi[300001]; void dfs(int now, int p){ for(int i=0; i<edge[now].size(); i++){ if(edge[now][i].first == p) continue; chi[now].PB(MP(edge[now][i].second, edge[now][i].first)); par[edge[now][i].first] = now; dfs(edge[now][i].first, now); } sort(chi[now].begin(), chi[now].end()); } int main(){ scanf("%d%d", &N, &M); for(int i=0; i<N+M; i++){ int P; LL C; C--; scanf("%d%lld", &P, &C); edge[i].PB(MP(P, C)); edge[P].PB(MP(i, C)); } par[0] = -1; dfs(0, -1); cout << 0 << endl; }

fireworks.cpp: In function 'void dfs(int, int)':
fireworks.cpp:15:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0; i<edge[now].size(); i++){
               ~^~~~~~~~~~~~~~~~~
fireworks.cpp: In function 'int main()':
fireworks.cpp:25:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d", &N, &M);
  ~~~~~^~~~~~~~~~~~~~~~
fireworks.cpp:30:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d%lld", &P, &C);
   ~~~~~^~~~~~~~~~~~~~~~~~