暑期特训——2023河南省赛

A（模拟）

题目大意

输入输出

题目思路

• 枚举下标i，从左往右枚举，直到出现重复字符
• 判断s[i + 1：] 是否是回文串
• 注意:题目中说a和b是非空的

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题目代码

from sys import stdin, setrecursionlimit

setrecursionlimit(100000)
input = lambda: stdin.readline().strip()

r1 = lambda: int(input())
r2 = lambda: map(int, input().split())
r3 = lambda: [*map(int, input().split())]


def solve():
    s = input()
	
    if len(s) == 1:
        print("NaN")
        return

    st = set()
    for i,x in enumerate(s):
        if x in st:
            break
        if s[i + 1:] == s[i + 1:][::-1]:
            print("HE")
            return
        st.add(x)
    print("NaN")


if __name__ == '__main__':
    t = r1()
    for _ in range(t):
        solve()