Leetcode 139. Word Break 动态规划

解法参考:https://blog.csdn.net/yujin753/article/details/48010677

Given a non-empty string s and a dictionary wordDict containing a list of non-empty words, determine if s can be segmented into a space-separated sequence of one or more dictionary words.

Note:

  • The same word in the dictionary may be reused multiple times in the segmentation.
  • You may assume the dictionary does not contain duplicate words.

Example 1:

Input: s = "leetcode", wordDict = ["leet", "code"]
Output: true
Explanation: Return true because "leetcode" can be segmented as "leet code".

Example 2:

Input: s = "applepenapple", wordDict = ["apple", "pen"]
Output: true
Explanation: Return true because "applepenapple" can be segmented as "apple pen apple".
             Note that you are allowed to reuse a dictionary word.

Example 3:

Input: s = "catsandog", wordDict = ["cats", "dog", "sand", "and", "cat"]
Output: false
class Solution {
public:
    bool wordBreak(string s, vector<string>& wordDict)
	{
		//边界条件 他说了不空 没有边界
		//动态规划 一个个字符判断 必须前面是true在加上一个存在的字符串才可以
		vector<bool> dp(s.size()+1,false);
		int size = s.size();
		dp[0] = true;
		for (int i = 1; i <= size; i++) 
		{
			for (int j = 0; j < i; j++) 
			{
				if (dp[j] && find(wordDict.begin(), wordDict.end(), s.substr(j,i-j)) != wordDict.end()) 
				{
					dp[i] = true;
					break;
				}
			}
		}
		//find(s.cbegin(),s.cend(),'1');
		return dp[size];
	}
};

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转载自blog.csdn.net/BJUT_bluecat/article/details/80939421