Compilare: main.cpp: In function 'int main()': main.cpp:32:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(sol[i.first].size()>k) sol[i.first].erase(sol[i.first].begin()+k, sol[i.first].end()); ~~~~~~~~~~~~~~~~~~~^~ main.cpp:17:37: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("pitici.in", "r", stdin); ^ main.cpp:18:39: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("pitici.out", "w", stdout); ^ main.cpp:19:32: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d", &n, &m, &k); ^ main.cpp:22:36: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d", &x, &y, &z); ^