2020-09-03 删数问题

https://www.luogu.com.cn/problem/P1106

#include <iostream>
#include <cstdio>
#include <cstring>
#include <cmath>
#include <sstream>
#include <algorithm>
#include <cstring>
#include <vector>
using namespace std;

template<typename DataType>
DataType qmi(DataType m, int k)
{
    DataType res = 1, t = m;
    while (k)
    {
        if (k&1) res = res * t;
        t = t * t;
        k >>= 1;
    }
    return res;
}

int read(){
    int x = 0,f = 1;
    char c = getchar();
    while (c<'0'||c>'9') {
        if (c=='-') {
            f = -1;
        }
        c = getchar();
    }
    while (c>='0'&&c<='9') {
        x = x*10+c-'0';
        c = getchar();
    }
    return x*f;
}

#define fi(a,b) for(int i = a; i <= b; i++)
#define fj(a,b) for(int j = a; j >= b; j--)

struct MAP{
    int pos;
    int data;
};

void quickSort(MAP *a,int left,int right){
    int i,j;
    
    MAP temp,t;
    
    temp = a[(left+right)/2];//基准值
    
    i = left;
    j = right;
    
    while(i<=j){
        while (a[j].data > temp.data) {
            j--;
        }
        
        while (a[i].data < temp.data) {
            i++;
        }
        
        if (i<=j) {
            t = a[i];
            a[i] = a[j];
            a[j] = t;
            //继续下一步
            i++;
            j--;
        }
        
    }
    
    if(left<j)quickSort(a,left, j);//继续分治
    if(i<right)quickSort(a,i, right);//继续分治
}

//const int maxNum = 255;
//MAP num[maxNum];
//MAP num1[maxNum];

int n,k,a[257],rest,t=1,minp,cnt=0;
bool flag = 0;
string num;
int main(){
    cin>>num>>k;
    n = num.length();
    for(int i = 1; i <= n ; ++i){
        a[i]=num[i-1]-'0';
    }
    rest = n-k;
    while(cnt < rest){
        minp = t;//最大值的位置
        for(int i = t; i <= k+t; ++i){//寻找最大值的位置
            if(a[minp] > a[i])minp = i;
        }
        if(a[minp])
            flag=1;
        if(flag)
            cout<<a[minp];
        k -= (minp-t);
        t = minp+1;
        cnt++;
    }
    if(!flag)cout<<0;
    return 0;
}
/*
175438
4
============
13
*/