Compilare: main.cpp: In function 'int main()': main.cpp:47:20: warning: unused variable 'B' [-Wunused-variable] double B = a[i].x - b[j].x; ^ main.cpp:58:20: warning: unused variable 'B' [-Wunused-variable] double B = a[i].x - b[j].x; ^ main.cpp:97:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < R.size() ; ++i) ~~^~~~~~~~~~ main.cpp:23:36: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("elmer.in", "r", stdin); ^ main.cpp:24:38: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("elmer.out", "w", stdout); ^ main.cpp:26:20: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ main.cpp:28:40: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &a[i].x, &a[i].y); ^ main.cpp:30:20: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &m); ^ main.cpp:32:40: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &b[i].x, &b[i].y); ^