Compilare: main.cpp: In function 'int main()': main.cpp:27:29: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("mexc.in","r",stdin); ^ main.cpp:28:31: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("mexc.out","w",stdout); ^ main.cpp:31:25: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d",&n,&m,&d); ^ main.cpp:34:74: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&v[i][j]),g[v[i][j]].push_back({i,j}),maxim=max(maxim,v[i][j]); ^