Add partition sort algorithm

This commit is contained in:
danghai 2019-05-04 12:53:11 -07:00
parent 2fde23c6ed
commit 261caac197
1 changed files with 62 additions and 0 deletions

62
sorting/partitionSort.c Normal file
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#include <stdlib.h>
#include <stdio.h>
void swap(int *a, int *b) {
int tmp = *a;
*a = *b;
*b = tmp;
}
int partition(int arr[], int low, int high) {
int pivot = arr[low];
int i = low - 1, j = high + 1;
while(1) {
/* Find leftmost element >= pivot */
do {
i++;
} while(arr[i] < pivot);
/* Find rightmost element <= pivot */
do {
j--;
} while(arr[j] > pivot);
/* if two pointers met */
if (i >= j)
return j;
swap(&arr[i], &arr[j]);
}
}
void partitionSort(int arr[], int low, int high) {
if(low < high) {
int value = partition(arr, low, high);
partitionSort(arr, low, value);
partitionSort(arr, value + 1, high);
}
}
void printArray(int arr[], int n) {
int i;
for(i = 0; i < n; i++)
printf("%d ", arr[i]);
printf("\n");
}
int main() {
int arr[20];
int i, range = 100;
for(i = 0; i < 20; i++) {
arr[i] = rand() % range + 1;
}
int size = sizeof arr / sizeof arr[0];
printf("Array: \n");
printArray(arr, size);
partitionSort(arr, 0, size - 1);
printf("Sorted Array: \n");
printArray(arr, size);
return 0;
}