HDU 3183 A Magic Lamp

直接模拟   如果后一位比前一位小，那就一直 向前 pop（）掉 维护他单调递增；

#include<iostream>
#include<cstring>
#include<algorithm>
#include<cmath>
#include<stdio.h>
#include<vector>
using namespace std;

char str[1123]; int res[1123],num;
int main( )
{
    while( scanf("%s%d",&str,&num) != EOF )
    {
        int len = strlen( str ); int k = 0;
        for( int i = 0; i < len; i++ )
        if( k != 0 && num != 0 && (str[i] - '0') < res[k] )
        {
            while( k != 0 && num != 0 && (str[i] - '0') < res[k] ){
                 k--; num--;
            }
              res[++k] = ( str[i] - '0' );
        }else res[++k] = ( str[i] - '0' );
         while( num-- && k != 0 )k--;
         bool fell = false; bool fall = false;
        for( int i = 1; i <= k; i++ )
        if(  res[i] == 0  ){ if( fell )cout<<res[i]; }
        else { fell = true; cout<<res[i]; }
        if( !fell ) cout<<0;puts("");
    }
    return 0;
}