Compilare: user.cpp: In function ‘int solve(int, int, int, int)’: user.cpp:24:24: warning: variable ‘Ns’ set but not used [-Wunused-but-set-variable] int s = 0, Ns = 1; ^ user.cpp: In function ‘int main()’: user.cpp:49:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("treid.in", "r", stdin); ^ user.cpp:50:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("treid.out", "w", stdout); ^ user.cpp:51:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &n, &m); ^ user.cpp:54:34: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &a[i][j]); ^