uva-256超时了，怎么回事啊？求解答

#include <stdio.h>#include <math.h>long x;long y;int n=2;int numLenth(long num){int i=0;if(num==0)return 1;while(num){num/=10;i++;}return i;}int split(int num){int i,j;x=num/(pow(10,n/2));y=num%((long)pow(10,n/2));long tem=x+y;if( (tem*tem) == num){j=numLenth(num);if(j==n){printf("%d\n",num);}else{for(i=0;i<n-j;i++)printf("0");printf("%d\n",num);}}return 0;}int main(){int i;long sum;while(scanf("%d",&n)!=EOF){sum=pow(10,n)-1;for(i=0;i<=sum;i++){split(i);}}return 0;}