10测试点WA了，不知道为什么输出的比测试点要少一天

```#include<bits/stdc++.h>
using namespace std;
int sum;
bool hw(int x){
    int a[8];
    for(int i = 1; i <= 8; i++){
        a[i] = x % 10;
        x /= 10;
    }
    int xsum = 0;
    for(int i = 1; i <= 4; i++){
        if(a[i] == a[8-i+1]) xsum++;
    }
    if(xsum == 4) return 1;
    else return 0;
}
bool ry(int x){
    x /= 10000;
    if(x % 4 == 0 && x / 100 != 0) return 1;
    else if(x % 400 == 0) return 1;
    else return 0;
}

int main(){
    int sd,ed; cin >> sd >> ed;
    for(int i = sd; i <= ed; i++){
        int msd = (i % 10000) / 100;
        int day = i % 100;
        if(hw(i)) sum++;
        if(msd == 2){
            if(ry(i) && day == 29) i += 100, i -= 29;
            if(!ry(i) && day == 28) i += 100, i -= 28; 
        }
        if( (msd == 1 || msd == 3 || msd == 5 || msd == 7 || msd == 8 || msd == 10) && day == 31){
            i += 100; i -= 31;
        }
        if( (msd == 4 || msd == 6 || msd == 9 || msd == 11) && day == 30){
            i += 100; i -= 30;
        }
        if(msd == 12 && day == 31){
            i -= 1231; i += 101; i += 10000;
        }
    }
    cout << sum;
    return 0;
}