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题目链接：https://ac.nowcoder.com/acm/contest/1877/S小乐乐与字符串题目描述在庆祝祖国母亲70华诞之际，老师给小乐乐出了一个问题。大家都知道China的英文缩写是CHN，那么给你一个字符串s，你需要做的是统计s中子串“CHN”的个数。子串的定义：存在任意下标a < b < c，那么“s[a]s[b]s[c]”就构成s的一个子串。如“ABC...

B. Zero ArrayYou are given an array a1,a2,…,an.In one operation you can choose two elements ai and aj (i≠j) and decrease each of them by one.You need to check whether it is possible to make all the...