Compilare: user.cpp: In function ‘int main()’: user.cpp:53:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(i1 < a[i].size() && i2 < b[i].size()) ^ user.cpp:53:44: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(i1 < a[i].size() && i2 < b[i].size()) ^ user.cpp:70:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<ans.size(); i++) ^ user.cpp:27:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("stalpi3.in", "r", stdin); ^ user.cpp:28:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("stalpi3.out", "w", stdout); ^ user.cpp:30:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &d); ^ user.cpp:35:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &x, &c); ^ user.cpp:42:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &x, &c); ^ user.cpp:67:59: warning: ‘Mini2’ may be used uninitialized in this function [-Wmaybe-uninitialized] ans.push_back(pair <int, int> (a[i][Mini1].i, b[i][Mini2].i)); ^ user.cpp:67:44: warning: ‘Mini1’ may be used uninitialized in this function [-Wmaybe-uninitialized] ans.push_back(pair <int, int> (a[i][Mini1].i, b[i][Mini2].i)); ^