Word Break

Word Break

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) {

        int n=s.size();

        unordered_map<string,int> mp;

        int l=0;

        for(auto w:wordDict)

        {

            mp[w]++;

            int k=w.size();

            l=max(l,k);

        }

        

        vector<bool> dp(n+1,false);

        dp[0]=true;

        for(int i=1;i<=n;++i)

        {

            for(int j=0;j<i;++j)

            {

                if(!dp[j]||(i-j>l))continue;

                if(mp.find(s.substr(j,i-j))!=mp.end())

                {

                    dp[i]=true;

                    break;

                }

            }

        }

        return dp[n];

    }

};