题解 | #字符串字符匹配#

while True:
    try:
        s1 = input()
        s2 = input()
        s = "abcdefghijklmnopqrstuvwxyz"

        sig = 'true'
        for s_i in s:
            if s_i in s1 and s_i not in s2:
                sig = 'false'
                break
        print(sig)

    except:
        break

时间复杂度：O(1)

空间复杂度：O(n)