Compilare: user.cpp: In function ‘int main()’: user.cpp:49:25: warning: unused variable ‘ok’ [-Wunused-variable] int i, j, m, n, k = 0, ok, r = 0; ^ user.cpp:49:29: warning: unused variable ‘r’ [-Wunused-variable] int i, j, m, n, k = 0, ok, r = 0; ^ user.cpp:45:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("cruce.in", "r", stdin); ^ user.cpp:46:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("cruce.out", "w", stdout); ^ user.cpp:51:23: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &m); ^ user.cpp:54:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%s", a[i]); ^