我写的估计有些麻烦了  但是将就着能运行出正确结果
#include <stdio.h>
#include <stdlib.h>
void main()
{
char a[]="742683613984";
char s[4];
char temp1[2];
char temp2[2];
char temp3[2];
char temp4[2];
int i,x,y,z;  //定义了需要删除的四个数的下标
int min=9999,n=0,b=8;
for(i=0;i<9;i++)
  for(x=i+1;x<10;x++)
   for(y=i+2;y<11;y++)
    for(z=i+3;z<12;z++)
    {
     temp1[0] =a[i];
     temp1[1] = '\0';
     temp2[0] =a[x];
     temp2[1] = '\0';
     temp3[0] =a[y];
     temp3[1] = '\0';
     temp4[0] =a[z];
     temp4[1] = '\0';
     n=(atoi(temp1)*1000+atoi(temp2)*100+atoi(temp3)*10+atoi(temp4));
     if(min>n)
      {
          min=n;
          s[0]=a[i];
          s[1]=a[x];
          s[2]=a[y];
          s[3]=a[z];

      }
    }
       for(int zz=0;zz<4;zz++) printf("%5c",s[zz]);
       printf("\n");
       printf("%d\n",min);



}