Compilare: main.cpp: In function 'int main()': main.cpp:149:18: warning: unused variable 'k' [-Wunused-variable] int n, i, j, k; ^ main.cpp:146:39: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("biscuiti.in", "r", stdin); ^ main.cpp:147:41: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("biscuiti.out", "w", stdout); ^ main.cpp:151:20: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ main.cpp:154:24: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &j); ^