Compilare: main.cpp: In function 'int main()': main.cpp:66:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int k = 0; k < vec[nrr].size(); k++) { ~~^~~~~~~~~~~~~~~~~ main.cpp:58:37: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("showroom.in", "r", stdin); ^ main.cpp:59:39: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("showroom.out", "w", stdout); ^ main.cpp:70:21: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%c", &ch); ^ main.cpp:80:23: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%c", &ch); ^