Compilare: main.cpp: In function 'int main()': main.cpp:24:8: warning: unused variable 'ch' [-Wunused-variable] char ch; ^~ main.cpp:21:38: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("marceland.in", "r", stdin); ^ main.cpp:22:40: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("marceland.out", "w", stdout); ^ main.cpp:25:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &t); ^ main.cpp:27:27: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d ", &n, &m); ^