leetcode 139 Word Break(阿里测试岗笔试题)

Given a string s and a dictionary of words dict, determine if s can be segmented into a space-separated sequence of one or more dictionary words.

For example, given

s =

"leetcode"

,

dict =

["leet", "code"]

.

Return true because

"leetcode"

can be segmented as

"leet
code"

.

class Solution {
public:
bool wordBreak(string s, unordered_set<string>& wordDict) {
vector<bool> qie(s.length()+1,false);
qie[0]=true;
for(int i=1;i<s.length()+1;++i){

for(int j=i-1;j>=0;--j)
{
if(qie[j]&&wordDict.find(s.substr(j,i-j))!=wordDict.end()){
qie[i]=true;
break;
}
}

}
return qie[s.length()];

}
};