冒泡排序，前面几个没有排序

#include "stdafx.h"
#include <iostream>
using namespace std;
template<typename T>
//整数或浮点数皆可使用
void bubble_sort(T arr[], int len,int index=0)
{
    int i, j;  T temp;
    for (i = 0; i < len - 1; i++)
        for (j = index; j < len - 1 - i; j++)
            if (arr[j] < arr[j + 1])
            {
                temp = arr[j];
                arr[j] = arr[j + 1];
                arr[j + 1] = temp;
            }
}
int main()
{
    int arr[] = { 61, 17, 29, 22, 34, 60, 72, 21, 50, 1, 62 };
    int len = (int) sizeof(arr) / sizeof(*arr);
    bubble_sort(arr, len);
    for (int i = 0; i < len; i++)
        cout << arr[i] << ' ';

    cout << endl;

    float arrf[] = { 17.5, 19.1, 0.6, 1.9, 10.5, 12.4, 3.8, 19.7, 1.5, 25.4, 28.6, 4.4, 23.8, 5.4 };
    int len = (int) sizeof(arrf) / sizeof(*arrf);
    bubble_sort(arrf, len,3);
    for (int i = 0; i < len; i++)
        cout << arrf[i] << ' ';

    getchar();
    return 0;
}