下列程序运行结果为____。#include <iostream.h>void main(){int a[4][4]={{1,4,3,2},{8,6,5,7},{3,7,2,5},{4,8,6,1}},i,j,k,t;for(i=0;i<4;i++)for(j=0;j<3;j++)for(k=j+1;k<4;k++)if(a[j][i]>a[k][i]){t=a[j][i];a[j][i]=a[k][i];a[k][i]=t;} /*按列排序*/for(i=0;i<4;i++)cout<<a[i][i];cout<<endl;}