PRoblem Description

Input

Output

Example Input

4 21 21 32 23 4
Example Output
3
Hint
 
Author
lin
快速排序。。。。
01
#include<stdio.h>
02
void dog(int a[], int l, int r);
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int main()
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{
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    int i, n, b, c, num, m, a[100000];
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    while(scanf("%d%d", &n, &m) != EOF)
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    {
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        for(i = 0; i < n; i++)
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        {
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            scanf("%d%d", &b, &c);
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            a[i] = c - b;
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        }
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        dog(a, 0, n - 1);
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        i = n - 1;
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        num = 0;
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        while(m >  0)
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        {
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            num += a[i];
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            i--;
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            m--;
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        }
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        printf("%d/n", num);
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    }
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    return 0;
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}
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void dog(int a[], int l, int r)
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{
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    if(l < r)
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    {
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        int i = l, j = r, x = a[l];
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        while(i < j)
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        {
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            while(i < j && a[j] >= x)
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                j--;
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            if(i < j)
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                a[i++] = a[j];
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            while(i < j && a[i] < x)
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                i++;
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            if(i < j)
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                a[j--] = a[i];
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        }
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        a[i] = x;
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        dog(a, l, i - 1);
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        dog(a, i + 1, r);
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    }
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    else return;
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}