Compilare: user.cpp: In function ‘int main()’: user.cpp:39:24: warning: unused variable ‘len’ [-Wunused-variable] int d, i, m, a, j, k, len, inew, jnew, knew; ^ user.cpp:37:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("alge.in", "r", stdin); ^ user.cpp:38:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("alge.out", "w", stdout); ^ user.cpp:41:23: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &m); ^ user.cpp:43:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d", &i, &j, &k); ^