Compilare: main.cpp: In function 'int main()': main.cpp:57:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j = 0 ; j < modif[i].size() ; j ++) ~~^~~~~~~~~~~~~~~~~ main.cpp:75:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j = 0 ; j < modif[i].size() ; j ++) ~~^~~~~~~~~~~~~~~~~ main.cpp:34:37: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("blis.in" , "r" , stdin); ^ main.cpp:35:39: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("blis.out" , "w" , stdout); ^ main.cpp:37:21: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d" , &k); ^