洛谷 P1015 [NOIP 1999 普及组] 回文数

审题不清晰，一开始没注意到按进制来输入数字，拿int去存，调试了半天，写着写着成shit了，实在没办法。。思路很简单的，就是字符串模拟加法，测试点是没有考虑到一开始就是回文数的情况的，所以不用管88 99这种数据到底按0还是往后算。

AcCode：

#include<iostream>
#include<cstring>
#include<algorithm>
#include<map>
using namespace std;
map<char, int> mp;
char a[16] = {'0','1','2','3','4','5','6','7','8','9','A','B','C','D','E','F'};
string add(string x, int rx){
	string ans = "";
	int j = 0;
	for(int i = 0; i < x.length(); i++){
		int h = mp[x[x.length() - 1 - i]] + mp[x[i]] + j;
		//cout << h << endl;
		ans += a[h % rx];
		j = h / rx;
	}
	if(j > 0) ans += a[j];
	reverse(ans.begin(), ans.end());
	int f = 0, b = ans.length() - 1;
	bool flag = true;
	while(f < b){
		if(ans[f++] != ans[b--]) flag = false;
	}
	if(flag) return "yes";
	else return ans;
}

int main(){
	//cout << add("87", 16);
	string M;
	int N, ans = 0;
	cin >> N >> M;
	for(int i = 0; i <= 9; i++){
		mp[(char)(i + '0')] = i;
	}
	mp['A'] = 10;
	mp['B'] = 11;
	mp['C'] = 12;
	mp['D'] = 13;
	mp['E'] = 14;
	mp['F'] = 15;
	for(int i = 1; i <= 30; i++){
		M = add(M, N);
		if(M == "yes") {
			cout << "STEP=" << i << endl;
			return 0; 
		}
	}
	cout << "Impossible!";
	return 0;
}