Compilare: user.cpp: In function ‘void readdata()’: user.cpp:91:9: warning: unused variable ‘j’ [-Wunused-variable] int j=0,pr=1; ^ user.cpp:97:33: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buff,1,1024,stdin); ^ user.cpp: In function ‘int main()’: user.cpp:123:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("jap.in","r",stdin); ^ user.cpp:124:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("jap.out","w",stdout); ^ user.cpp:125:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&t); ^