Compilare: main.cpp: In function 'int bfs()': main.cpp:37:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j = 0 ; j < G[u].size() ; j ++) ~~^~~~~~~~~~~~~ main.cpp: In function 'int update_flow()': main.cpp:63:1: warning: no return statement in function returning non-void [-Wreturn-type] } ^ main.cpp: In function 'void max_flow()': main.cpp:68:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j = 0 ; j < G[t].size() ; j ++) ~~^~~~~~~~~~~~~ main.cpp: In function 'void bfs2(int, int, int*)': main.cpp:95:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j = 0 ; j < G[u].size() ; j ++) ~~^~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:109:40: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("critice.in" , "r" , stdin); ^ main.cpp:110:42: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("critice.out" , "w" , stdout); ^ main.cpp:112:28: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d" , &n , &m); ^ main.cpp:115:39: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d" , &x , &y , &z); ^