Compilare: user.cpp: In function ‘char nextch()’: user.cpp:15:31: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buf,1,MAXBUF,fi); ^ user.cpp: In function ‘int main()’: user.cpp:97:44: warning: ‘val’ may be used uninitialized in this function [-Wmaybe-uninitialized] if((x1+nr1)%MOD1==(nr3*(mat[1][i-n+1]+val))%MOD1&&(x2+nr2)%MOD2==(nr4*(mat[1][i-n+1]+val))%MOD2) ^