foo.cc: In function 'int main()':
foo.cc:20:27: warning: suggest parentheses around assignment used as truth value [-Wparentheses]
        if (a[j][k]=a[j][h])pd=0;
                           ^
foo.cc:28:27: warning: suggest parentheses around assignment used as truth value [-Wparentheses]
        if (a[k][j]=a[h][j])pd=0;
                           ^
foo.cc:36:27: warning: suggest parentheses around assignment used as truth value [-Wparentheses]
        if (a[k][l]=a[j][h])pd=0;
                           ^
foo.cc:41:23: warning: unused variable 'c' [-Wunused-variable]
        if(i<n-1) char c=cin.get(); 
                       ^

自豪的采用jd5进行评测(github.com/masnn/jd5)