LeetCode OJ - Valid Number

LeetCode OJ - Valid Number

 發現一個不錯的解法～

See Problem!

	class Solution {
	public:
	bool isNumber(const char *s) {
	bool point = false, notation = false;
	int len = strlen(s);
	int start = 0, end = len;
	for(int i = start; i < end; i++)
	if(s[i] == ' ') start++;
	else break;
	for(int i = end - 1; i >= 0; i--)
	if(s[i] == ' ') end--;
	else break;
	if(start >= end) return false;
	if(s[start] == '+' || s[start] == '-')
	start++;
	if(s[start] == '.' && ((s[start + 1] < '0') || (s[start + 1] > '9')))
	return false;//special case '.'
	/* this case is right in this problem
	if(s[start] > '9'|| s[start] < '0')
	return false;// in case ".0887"
	*/
	if(s[start] == 'e') return false;
	for(int i = start; i < end; i++){
	if(s[i] <= '9' && s[i] >= '0') continue;
	else if(s[i] == '.'){
	start = i + 1;// ex: 904.[4]2
	point = true;
	break;
	}
	else if(s[i] == 'e'){
	start = i + 1;
	if(s[start] == '+' || s[start] == '-')
	start++;
	notation = true;
	break;
	}
	else return false;
	}
	if(point){
	if(start >= end) return true; //ex: "90932."
	//if(s[start] > '9' || s[start] < '0') return false;
	for(int i = start; i < end; i++){
	if(s[i] <= '9' && s[i] >= '0') continue;
	else if(s[i] == 'e'){
	start = i + 1;
	if(s[start] == '+' || s[start] == '-')
	start++;
	notation = true;
	break;
	}
	else return false;
	}
	}
	if(notation){
	if(start >= end) return false;
	else if(s[start] > '9' || s[start] < '0') return false;
	for(int i = start; i < end; i++)
	if(s[i] <= '9' && s[i] >= '0') continue;
	else return false;
	}
	return true;
	}
	};

view raw LeetCode OJ - Valid Number.cpp hosted with ❤ by GitHub

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