Greedy - deletion

Catalog

Preface

Topic introduction

sample input :

sample output :

analysis

The theory exists , Practice begins ！

Code ：

matters needing attention ： 

Love is worth years. Love is worth years .

Preface

Number of deletions ！！！！！！！！！！！！！！！！！！！！！！！！！！！！！！！！！！！！！！

Topic introduction

sample input :

178543  4

sample output :

13

Before starting, you can write it yourself to see if you can write it yourself ~ Pay attention to the output format ！

analysis

Greedy strategy , Find the number whose later number is greater than the previous number, and then ！ Delete him , You can minimize the remaining number ！

The theory exists , Practice begins ！

Code ：

#include <stdio.h>
#include <string.h>

int main()
{

    int s,w,i;
    char a[101];

    scanf("%s%d",a,&s);

    while (s)// If s==0 Then direct output is good ！
        
    {
        
        w=strlen(a);
        i=0;
    
        while(i<w&&a[i]<=a[i+1])// Traverse each number 
        {
            i++;
        }
        // find a[i]>a[i+1] The number of 

        while (i<w)
        {
            a[i]=a[i+1];// Move the array forward and delete it a[i]
            i++;
        }
        
        s--;// Delete a number until there is no need to delete 
        
    }
    
    int j=0;
    
    while (a[0] =='0')// If the first digit is 0;
    {
        
         while (j<w)
        {
            a[j]=a[j+1];// Move array forward 
            j++;
        }
        j=0;// hold j Revert to the first one for next recycling 
        
    }
    
    if(a[0]==0)// At this point if a[0] also ==0 So there's only 0 了 
    printf("0\n");
    else
    printf("%s\n",a);
    
    return 0;
}

matters needing attention ： 

1. I think so.

  This while It's very essential to use .

2. Consider that the first number equals 0 The situation of , If the first number equals 0, Then remove it .

3. Want to consider a[0]==0 Otherwise, it cannot be output

ok The conclusion is over  

Love is worth years.
Love is worth years .