Compilare: main.cpp: In function 'int main()': main.cpp:126:31: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen ( in, "r", stdin ); ^ main.cpp:127:33: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen ( out, "w", stdout ); ^ main.cpp:131:34: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf( "%d%d%d", &N, &M, &K ); ^ main.cpp:133:30: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf ( "%d", (f+i) ); ^ main.cpp:136:42: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf ( "%d%d%d", &i, &j, &cost ); ^