快速排序(C語言)

標籤：快速排序   遞迴   非遞迴   

非遞迴：

#include <stdio.h>#include <stdlib.h>int partition(int s[], int i, int j){int value = 0;int flag = 1; //判斷該從頭迴圈還是尾迴圈value = s[i];while(i<j){switch(flag){case 0:if(s[i] < value)i++;else{s[j--] = s[i];flag = 1;}break;case 1:if(s[j] >= value)j--;else{s[i++] = s[j];flag = 0;}break;}}s[i] = value;return i;}void quick_sort(int s[], int l, int r){int *stack = (int *)malloc(sizeof(int)*(r-l+1));int top = 0;int index1, index2;int res;stack[top++] = r;stack[top++] = l;while(top!=0){index1 = stack[--top];index2 = stack[--top];res = partition(s, index1, index2);if(res != index2) //後部分partiton未結束{stack[top++] = index2;stack[top++] = res+1;}if(res != index1) //前部分partion未結束{stack[top++] = res-1;stack[top++] = index1;}}free(stack);stack = NULL;}int main(){int number[10] = {8, 1, 8, 4, 9, 5, 8, 10, 3, 6};quick_sort(number, 0, 9);int i;for(i=0; i<10; i++){printf("%d, ", number[i]);}printf("\n");return 0;}

遞迴：

#include <stdio.h>#include <stdlib.h>int partition(int s[], int i, int j){int value = 0;int flag = 1; //判斷該從頭迴圈還是尾迴圈value = s[i];while(i<j){switch(flag){case 0:if(s[i] < value)i++;else{s[j--] = s[i];flag = 1;}break;case 1:if(s[j] >= value)j--;else{s[i++] = s[j];flag = 0;}break;}}s[i] = value;return i;}void quick_sort(int s[], int l, int r){int res;if(l<r){res = partition(s, l, r);quick_sort(s, l, res-1);quick_sort(s, res+1, r);}}int main(){int number[10] = {8, 1, 8, 4, 9, 5, 8, 10, 3, 6};quick_sort(number, 0, 9);int i;for(i=0; i<10; i++){printf("%d, ", number[i]);}printf("\n");return 0;}

快速排序(C語言)