POJ 2388 Who's in the Middle 排序

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题意：输出一串数字的中间数。
题解：

#include <iostream>using namespace std;void quiksort ( int * array, int left, int right ){if ( left < right ){int s = array [( left + right ) / 2];        int l = left - 1, r = right + 1;        while ( 1 ){while ( array[++l] < s );         while ( array[--r] > s );        if ( l >= r )break;        swap ( array[l], array[r] );}        quiksort ( array, left, l - 1  );          quiksort ( array, r + 1, right );  }                                      }                                          int main(){int n, array[10010];cin >> n;for ( int i = 0; i < n; i++ )cin >> array[i];quiksort(array,0,n-1);cout << array[n/2] << endl;return 0;}或者#include <iostream>using namespace std;int array[10010];int part ( int left, int right ){int i = left - 1;int s = array[right];for ( int j = left; j < right; j++ ){if ( array[j] <= s ){i++;swap ( array[i], array[j] );}}swap ( array[right], array[i+1] );return i + 1;}void Qsort ( int left, int right ){if ( left >= right )return;int p = part ( left, right );Qsort(left,p-1);Qsort(p+1,right);}int main(){int n;cin >> n;for ( int i = 0; i < n; i++ )cin >> array[i];Qsort(0,n-1);cout << array[n/2] << endl;return 0;}