Compilare: user.cpp: In function ‘int main()’: user.cpp:29:18: warning: unused variable ‘j’ [-Wunused-variable] int n, k, i, j, sum,a, x, y, c1, c2, mij; ^ user.cpp:29:25: warning: unused variable ‘a’ [-Wunused-variable] int n, k, i, j, sum,a, x, y, c1, c2, mij; ^ user.cpp:27:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("kbetray.in", "r", stdin); ^ user.cpp:28:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("kbetray.out", "w", stdout); ^ user.cpp:30:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &k); ^ user.cpp:34:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &x, &y); ^ user.cpp:29:42: warning: ‘mij’ may be used uninitialized in this function [-Wmaybe-uninitialized] int n, k, i, j, sum,a, x, y, c1, c2, mij; ^