# 选择排序
a = [5,2,1,8,9,2,6,7]
for i in range(0,len(a)-1):
    min_i = i   # 设置最小值所对应的位置
    for j in range(i+1, len(a)):
        if a[j] < a[min_i]:
            min_i = j  # 更新最小值所对应的位置
    a[i],a[min_i] = a[min_i],a[i]  # 交换第i项和第最小值项
print(a)
'''
a = [5,2,1,8,9,2,6,7]
第一轮
i = 0  min_i = 0 
        j = 1  a[1] < a[0]? min_i = 1
        j = 2  a[2] < a[1]? min_i = 2
        j = 3  a[3] < a[2]? min_i = 2
        j = 4  a[4] < a[2]? min_i = 2
        j = 5  a[5] < a[min_i]? min_i = 2
        j = 6  a[j] < a[min_i]? min_i = 2
        j = 7  a[j] < a[min_i]? min_i = 2
a[i],a[min_i]交换 [1,2,5,8,9,2,6,7]
i = 1 min_i = 1
        j = 2 a[j]<a[min_i]? min_i = 1
        ...
...

'''