Compilare: main.cpp: In function 'int main()': main.cpp:71:107: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("fmcm.in","r",stdin),freopen("fmcm.out","w",stdout),fread(k,1,N,stdin),n=A(),m=A(),s=A(),t=A(); ^ main.cpp:71:107: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] main.cpp:71:107: warning: ignoring return value of 'size_t fread(void*, size_t, size_t, FILE*)', declared with attribute warn_unused_result [-Wunused-result]