画解算法 520-检测大写字母

[guanpengchn]

画解算法 520-检测大写字母

[dljgs1]

JS正则匹配求解：

var detectCapitalUse = function(word) {
    var ma = word.match(/[A-Z]?[a-z]+|[A-Z]+/);
    return ma[0].length == word.length && ma.index==0;
};

c++状态机求解(Runtime: 0 ms, faster than 100.00% of C++ online submissions for Detect Capital.)：

class Solution {
public:
	bool detectCapitalUse(string word) {
		if (word.length() <= 1)return true;
		auto judge = [](char c){return ('a' <= c && c <= 'z') ? 0 : 1; };
		int st = judge(word[0])*3;
		for (auto&c : word.substr(1)){
			int cur = judge(c);
			if (st-cur==1 || cur>st)return false;
			st = cur;
		}
		return true;
	}
};