求第K大源码

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#include <stdio.h>
#include <time.h>
#include <stdlib.h>

#define SWAP(A,B) {int t; t = (A); (A) = (B); (B) =t;}

int kbig(int number[], int left, int right, int k);

int partition(int number[], int left, int right);
void quicksort_m(int number[], int left, int right);
void quicksort(int number[], int left, int right);

int main(int argc, char* argv[]){

   int i = 0;
   int number[100];
   srand(time(NULL));
   for( i = 0; i< 100; i++)
   {
       number[i] = rand() % 100;
       printf("%d,", number[i]);
   }
   printf("\n\n");
   kbig(number, 0, 99, 10);
   for(i = 0 ; i<100; i++ )
       printf("%d,", number[i]);

   quicksort(number, 0, 99);
   printf("\n\n");
   for( i = 0; i< 100; i++)
   {
       printf("%d,", number[i]);
   }
   getchar();
   return 0;
}

int partition(int number[], int left, int right){
   int i,j ,s;

       i = left -1;
       j = right +1;
       SWAP(number[left], number[(left+right)/2]);
       s = number[left];
       while(1){
           while( number[++i] < s);
           while( number[--j] > s);
           if( i >= j )
               break;
           SWAP(number[i], number[j]);
       }
       number[left] = number[j];
       number[j] = s;
   return j;
}

int kbig(int number[], int left, int right, int k){
   int count = 0;
   if(right - left <= k)
       return left;
   count = partition(number,left,right);
   if( right - count > k)
       kbig(number, count+1,right,k);
   else if( right - count < k)
       kbig(number, left,count -1, k-right+count);
   else
       return count;
}

void quicksort(int number[], int left, int right){
   int j;
   if(left < right){
       j = partition(number,left,right);
       quicksort(number, left, j-1);
       quicksort(number, j+1, right);
   }
}
void quicksort_m(int number[], int left, int right)
{
   int i, j, s;
   if(left < right){
       i = left-1;
       j = right+1;
       SWAP(number[left], number[(left+right)/2]);
       s = number[left];

       while(1){
           while( number[++i] < s);
           while( number[--j] > s);
           if( i >= j)
               break;
           SWAP(number[i], number[j]);
       }
       number[left] = number[j];
       number[j] = s;
       quicksort_m(number, left, j-1);
       quicksort_m(number, j+1, right);
   }
}