Compilare: main.cpp: In function 'void solve()': main.cpp:44:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int k = 0; k < v[h2].size(); k ++) { ~~^~~~~~~~~~~~~~ main.cpp:47:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int k = 0; k < v[h1].size(); k ++) { ~~^~~~~~~~~~~~~~ main.cpp:54:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int k = 0; k < v[h].size(); k ++) { ~~^~~~~~~~~~~~~ main.cpp: In function 'void citire()': main.cpp:17:26: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &f, &t); ^ main.cpp:21:30: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &h, &x); ^ main.cpp: In function 'int main()': main.cpp:63:36: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("fft2d.in", "r", stdin); ^ main.cpp:64:38: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("fft2d.out", "w", stdout); ^