Compilare: main.cpp: In function 'int main()': main.cpp:90:40: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("atac2.in", "r", stdin); ^ main.cpp:91:42: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("atac2.out", "w", stdout); ^ main.cpp:93:41: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d %d", &n, &m, &k, &x); ^ main.cpp:94:52: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] for (int i = 1; i <= k; i++) scanf("%d", &a[i]); ^ main.cpp:97:31: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &u, &v); ^