Compilare: main.cpp: In function 'int main()': main.cpp:121:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (j=0; j<G[a[i]].size(); j++) ~^~~~~~~~~~~~~~~ main.cpp:96:32: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("pirati.in","r",stdin); ^ main.cpp:97:34: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("pirati.out","w",stdout); ^ main.cpp:98:30: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d\n",&N,&M,&Q); ^ main.cpp:100:29: warning: ignoring return value of 'char* fgets(char*, int, FILE*)', declared with attribute warn_unused_result [-Wunused-result] fgets(A[i]+1, M+10, stdin); ^ main.cpp:131:39: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d %d",&x1,&y1,&x2,&y2); ^