此代码只能判断三位回文数(求助大佬)

P1217 [USACO1.5] 回文质数 Prime Palindromes

ZBXALQX @ 2023-12-28 19:12:39

#include<bits/stdc++.h>
using namespace std;
bool is_p(int x){
for(int i=2;i<=sqrt(x);i++)
        if(x%i==0) return 0;
    return 1;
}
bool hw(int x){
    if(x/100==x%10)return 1;
    else return 0;
} 
int main(){
    int i,j;
    cin>>i>>j;
    for(i=1;i<=j;i++){
        if(is_p(i)&&hw(i))
        cout<<i<<endl;
    }
    return 0;
}

by ZBXALQX @ 2023-12-28 19:17:25

十万火急!!!在线等


by ZBXALQX @ 2023-12-28 19:43:19

@GXZJQ 我看不到你的回复啊


by SkyWave @ 2023-12-28 19:50:38

@ZBXALQX 偷懒的写法就是你可以先把数字转成字符串,判断反转后的和反转前的字符串相不相等就好了


by SkyWave @ 2023-12-28 19:51:40

bool check(int num) {
    string str = to_string(num);
    string rev = str;
    reverse(rev.begin(), rev.end());
    return str == rev;
}

by ChenDibang @ 2024-01-24 17:25:29

@SkyWave 超时


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