python - 如何让这个运行 'faster'？或者这是正确的术语吗？

Question

我是 python 新手，我为 Hackerrank 问题提交了此代码 Arrays and Simple Queries ，但对于大量测试用例，程序“由于超时而终止”。我怎样才能提高效率？

我已将主要交换功能粘贴在下面。(重复M次)

temp = input()
temp = temp.split(" ")
i = int(temp[1])-1
j = int(temp[2])-1
rep = (i-1)+1

if(temp[0]=='1') :
        rep = (i-1)+1
        while(i<=j) :
            count = i-1
            ex1 = count
            ex2 = i
            for k in range(0,rep) :
                arr[ex1], arr[ex2] = arr[ex2], arr[ex1]
                ex1 = ex1-1
                ex2 = ex2-1
            i = i+1
else :
    rep = (N-(j+1))
    while(j>=i) :
        count = j+1
        ex1 = count
        ex2 = j
        for k in range(0,rep) :
            arr[ex1], arr[ex2] = arr[ex2], arr[ex1]
            ex1 = ex1+1
            ex2 = ex2+1
        j=j-1

Answer 1

您可以尝试简单地连接切片，而不是使用许多循环:

def query(lst, t, start, end):
    # Convert to proper zero-indexed index
    start -= 1

    if t == '1':
        return lst[start:end] + lst[:start] + lst[end:]
    elif t == '2':
        return lst[:start] + lst[end:] + lst[start:end]


# Get the input however you want
N, M = map(int, input().split())
arr = list(map(int, input().split()))
assert len(arr) == N

for _ in range(M):
    t, start, end = input().split()
    arr = query(arr, t, int(start), int(end))

print(abs(arr[0] - arr[N - 1]))
print(*arr)

输入:

8 4
1 2 3 4 5 6 7 8
1 2 4
2 3 5
1 4 7
2 1 4

输出:

1
2 3 6 5 7 8 4 1