输出结果是社么
main(){
int n,i,j,k;
char s1[20],s2[20],s3[20];
printf("input :");
gets(s1)
printf("input :");
gets(s2)
printf(" :%d",n);
scanf("%d",&n);
for(i=0;i<n;i++)
s3[i]=s1[i];
for(j=0;j<n;j++)
s3[i+j]=s2[j];
for(k=n;s1[k]!='\0';k++)
s3[k+j]=s1[k];
s3[j+k]='\0';
printf(" %s:",s3);
}
