Compilare: main.cpp: In function 'int main()': main.cpp:17:35: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("sobo.in", "r", stdin); ^ main.cpp:18:37: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("sobo.out", "w", stdout); ^ main.cpp: In function 'void read()': main.cpp:26:30: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%lld%lld", &n, &l); ^ main.cpp:32:28: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%c", &c); ^ main.cpp:38:47: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] for(i=0; i<l; ++i) scanf("%lld", &cost[i]); ^