【常用代码】折半插入算法

王道的折半插入排序的代码太难懂了，上网搜了个这个看着比较好用
并且这个算法应该是不稳定的，同样的数值，后进来的插到前面去了。

// C program for implementation of
// binary insertion sort
#include <stdio.h>// A binary search based function
// to find the position
// where item should be inserted
// in a[low..high]
int binarySearch(int a[], int item,int low, int high)
{if (high <= low)return (item > a[low]) ?(low + 1) : low;int mid = (low + high) / 2;if (item == a[mid])return mid + 1;if (item > a[mid])return binarySearch(a, item,mid + 1, high);return binarySearch(a, item, low,mid - 1);
}// Function to sort an array a[] of size 'n'
void insertionSort(int a[], int n)
{int i, loc, j, k, selected;for (i = 1; i < n; ++i){j = i - 1;selected = a[i];// find location where selected should be insertedloc = binarySearch(a, selected, 0, j);// Move all elements after location to create spacewhile (j >= loc){a[j + 1] = a[j];j--;}a[j + 1] = selected;}
}// Driver Code
int main()
{int a[]= { 37, 23, 0, 17, 12, 72, 31, 46, 100, 88, 54 };int n = sizeof(a) / sizeof(a[0]), i;insertionSort(a, n);printf("Sorted array: \n");for (i = 0; i < n; i++)printf("%d ", a[i]);return 0;
}