Compilare: user.cpp: In function ‘int main()’: user.cpp:38:73: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int m=bin_search(0,(int)a[k].size()-1,i,k); m<a[k].size() && a[k][m]<=y; m++) ^ user.cpp: In function ‘int bin_search(int, int, int, int)’: user.cpp:18:1: warning: control reaches end of non-void function [-Wreturn-type] } ^ user.cpp: In function ‘int main()’: user.cpp:22:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("qxy.in" , "r", stdin); ^ user.cpp:23:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("qxy.out", "w", stdout); ^ user.cpp:24:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d\n", &n); ^ user.cpp:27:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &t); ^ user.cpp:32:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d\n", &q); ^ user.cpp:36:47: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d %d\n", &i, &j, &x, &y); ^