Compilare: main.cpp: In function 'int main()': main.cpp:30:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(k = 0 ; k < G[j].size() ; k ++) ~~^~~~~~~~~~~~~ main.cpp:34:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j = 0 ; j < G[0].size() ; j ++) ~~^~~~~~~~~~~~~ main.cpp:9:41: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("hamilton.in" , "r" , stdin); ^ main.cpp:10:43: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("hamilton.out" , "w" , stdout); ^ main.cpp:12:28: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d" , &n , &m); ^ main.cpp:18:39: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d" , &u , &v , &p); ^