Compilare: user.cpp: In function ‘int main()’: user.cpp:34:18: warning: unused variable ‘x’ [-Wunused-variable] int N, M, i, x, y, c,nrsol=0; ^ user.cpp:34:21: warning: unused variable ‘y’ [-Wunused-variable] int N, M, i, x, y, c,nrsol=0; ^ user.cpp:34:24: warning: unused variable ‘c’ [-Wunused-variable] int N, M, i, x, y, c,nrsol=0; ^ user.cpp:35:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("apm.in", "r", stdin); ^ user.cpp:36:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &N, &M); ^ user.cpp:40:44: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d", &X[i], &Y[i],&C[i]); ^ user.cpp:54:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("apm.out", "w", stdout); ^