Compilare: main.cpp: In function 'void solve()': main.cpp:62:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0; i<edges.size(); ++i) if(!flow[edges[i].first][edges[i].second]) out.push_back(i+1); ~^~~~~~~~~~~~~ main.cpp: In function 'void write()': main.cpp:67:38: warning: format '%d' expects argument of type 'int', but argument 2 has type 'std::vector<int>::size_type {aka long unsigned int}' [-Wformat=] printf("%d %d\n", out.size(), sol); ^ main.cpp: In function 'void read()': main.cpp:26:35: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("cmcm.in", "r", stdin); ^ main.cpp:27:32: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d", &n, &m, &e); ^ main.cpp:30:36: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d", &x, &y, &c); ^ main.cpp: In function 'void write()': main.cpp:66:37: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("cmcm.out", "w", stdout); ^