USACO习题：Dual Palindromes

和之前一道回文题目差不多，解法还是使用前文的方法。

核心方法参考如下：

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bool is_palindrome(int num,int base){
    int reversed = 0,temp=num;
    while(temp!=0){
        reversed = reversed*base + temp%base;
        temp/=base;
    }
    return (reversed==num);
}

 

题目完整代码：

View Code

#include <iostream>
#include <fstream>
#include <string>
#include <vector>
#include <algorithm>

using namespace std;

bool is_palindrome(int num,int base){
    int reversed = 0,temp=num;
    while(temp!=0){
        reversed = reversed*base + temp%base;
        temp/=base;
    }
    return (reversed==num);
}



int main() {
    ofstream fout("dualpal.out");
    ifstream fin("dualpal.in");

    int first_n=0,start=0;
    fin>>first_n>>start;
    
    int found = 0,pal_count=0;
    while(found<first_n){
        
        ++start;
        pal_count=0;
        for(int i=2;i<=10&&pal_count<2;++i){
            if(is_palindrome(start,i)){
                pal_count++;
                cout<<"base :"<<i<<",";
            }
            
            if(pal_count==2){
                fout<<start<<endl;
                found++;
                break;
            }
        }
        
        cout<<start<<":"<<pal_count<<endl;
    }

    fin.close();
    fout.close();
    return 0;
}