很重要的快速排序

今天再来个经常用的排序算法----快速排序！

</pre><p><pre name="code" class="cpp">int partition(int *A, int len){if(A==NULL||len<=0)return -1;//int pivot = ;//swap(&A[0], &A[pivot]);int key = A[0];int pre=0;int i=0;for(i=0; i<len; i++){if(A[i] < key){pre++;if(pre!=i)swap(&A[pre], &A[i]);}}swap(&A[pre], &A[0]);return pre;}void quickSort(int *A, int len){if(A==NULL||len<=0){return;}int pivot = partition(A, len);if(pivot < 0)return;quickSort(A, pivot);quickSort(A+pivot+1, len-pivot-1);}void printArray(int *A, int len){for(int i=0; i<len; i++){cout << A[i] << endl;}}