写在前面

  • 正确立即题目
  • permutation: 排列（方式）；组合（方式）
  • 通用方法
  • 循环遍历计算结果，拼成字符串
  • map封装大数字符次数结果，循环比较倍数结果与原数字符个数及种类
  • 不手生的情况下，10分钟内a题

测试用例

input:
1234567899
output:
Yes
2469135798

ac代码

  • 时间长手生，撸代码时间耗费偏多
#include<map>
#include<iostream>
#include<algorithm>
using namespace std;

int main()
{
    string in_num, res_num;
    cin >> in_num;

    int yushu = 0, tp_num=0;
    map<char, int> in_map, res_map;
    for(int i=in_num.size()-1; i>=0; i--)
    {
        tp_num = (in_num[i]-'0')*2;
        res_num += (yushu + tp_num%10 + '0');

        in_map[in_num[i]] +=1;
        res_map[yushu + tp_num%10 + '0'] +=1;

        yushu = tp_num/10;
    }
    if(yushu>0) res_num += (yushu+'0');
    reverse(res_num.begin(), res_num.end());

    string res_flag="Yes";
    if(res_num.size()!=in_num.size()) res_flag = "No";

    for(int i=0; i<in_num.size(); i++)
    {
        if(in_map[in_num[i]]!=res_map[in_num[i]])
        {
            res_flag = "No";
            break;
        }
    }
    cout << res_flag << endl;
    cout << res_num;

    return 0;
}
  • 部分优化
#include<map>
#include<iostream>
#include<algorithm>
using namespace std;
int main()
{

    string in_num, res_num;
    cin >> in_num;
    int yushu = 0, tp_num=0;
    map<char, int> in_map;
    for(int i=in_num.size()-1; i>=0; i--)
    {
        tp_num = (in_num[i]-'0')*2;
        res_num += (yushu + tp_num%10 + '0');

        in_map[in_num[i]] +=1;
        in_map[yushu + tp_num%10 + '0'] -=1;

        yushu = tp_num/10;
    }
    if(yushu>0) res_num += (yushu+'0');
    reverse(res_num.begin(), res_num.end());

    string res_flag="Yes";
    if(res_num.size()!=in_num.size()) res_flag = "No";

    for(int i=0; i<in_num.size(); i++)
    {
        if(in_map[in_num[i]]!=0)
        {
            res_flag = "No";
            break;
        }
    }

    printf("%s\n", res_flag.c_str());
    printf("%s", res_num.data());

    return 0;
}

参考代码

  • int book[10];
  • 循环统计。原数字符出现次数做加法，倍数结果字符出现次数做减法，最后结果为0，则Yes；否则为No
  • 优点: 节省资源、算力
#include <cstdio>
#include <string.h>
using namespace std;
int book[10];
int main() {
    char num[22];
    scanf("%s", num);
    int flag = 0, len = strlen(num);
    for(int i = len - 1; i >= 0; i--) {
        int temp = num[i] - '0';
        book[temp]++;
        temp = temp * 2 + flag;
        flag = 0;
        if(temp >= 10) {
            temp = temp - 10;
            flag = 1;
        }
        num[i] = (temp + '0');
        book[temp]--;
    }
    int flag1 = 0;
    for(int i = 0; i < 10; i++) {
        if(book[i] != 0)
            flag1 = 1;
    }
    printf("%s", (flag == 1 || flag1 == 1) ? "No\n" : "Yes\n");
    if(flag == 1) printf("1");
    printf("%s", num);
    return 0;
}