Compilare: user.cpp: In function ‘int main()’: user.cpp:12:27: warning: unused variable ‘ch’ [-Wunused-variable] int m = 2*n, i, j, k, ch; ^ user.cpp:13:22: warning: unused variable ‘tmp’ [-Wunused-variable] double mx[n][m], tmp, c; ^ user.cpp:7:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("bujor.in", "r", stdin); ^ user.cpp:8:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("bujor.out", "w", stdout); ^ user.cpp:9:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &T); ^ user.cpp:11:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ user.cpp:16:36: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lf", &mx[i][j]); ^