Project Euler problem 36

#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
#include <vector>
#include <queue>
#include <set>
#include <stack>
#include <cmath>
#include <map>
#include <ctime>
#define MAXN 111111
#define INF 100000007
using namespace std;
int a[1000001];
int cnt;
bool gao(int x)
{
string tmp1 = "", tmp2 = "";
while(x)
{
tmp1 = tmp1 + char(x % 2 + '0');
tmp2 = char(x % 2 + '0') + tmp2;
x /= 2;
}
if(tmp1 == tmp2) return 1;
return 0;
}
int main()
{
for(int i = 1; i <= 9; i++) a[cnt++] = i, a[cnt++] = i * 10 + i;
for(int i = 1; i <= 9; i++)
for(int j = 0; j <= 9; j++)
a[cnt++] = i * 100 + j * 10 + i, a[cnt++] = i * 1000 + j * 100 + j * 10 + i;
for(int i = 1; i <= 9; i++)
for(int j = 0; j <= 9; j++)
for(int k = 0; k <= 9; k++)
a[cnt++] = i * 10000 + j * 1000 + k * 100 + j * 10 + i, a[cnt++] = i * 100000 + j * 10000 + k * 1000 + k * 100 + j * 10 + i;
int ans = 0;
for(int i = 0; i < cnt; i++)
{
if(gao(a[i])) ans += a[i];
}
cout << ans << endl;
return 0;
}