标签:equal boolean false bsp 递归 动态规划 int lse n+1
//memo,记忆化搜索
class Solution {
int[][] memo;
public boolean wordBreak(String s, List<String> wordDict) {
int n=s.length();
memo=new int[n+1][n+1];
for(int i=0;i<=n;i++)
for(int j=0;j<=n;j++)
memo[i][j]=-1;
return breakWord(s,wordDict,0,n);
}
public boolean breakWord(String s,List<String> wordDict,int l,int r)
{
if(r==0)
return true;
if(memo[l][r]!=-1)
return memo[l][r]==1;
memo[l][r]=0;
for(int i=r-1;i>=0;i--)
{
if(helper(s.substring(i,r),wordDict)&&breakWord(s,wordDict,l,i))
{
memo[l][r]=1;
break;
}
}
return memo[l][r]==1;
}
public boolean helper(String s,List<String> wordDict)
{
for(String str:wordDict)
{
if(str.equals(s))
return true;
}
return false;
}
}
//动态规划
class Solution {
public boolean wordBreak(String s, List<String> wordDict) {
int n=s.length();
boolean[] dp=new boolean[n+1];
dp[0]=false;
for(int i=1;i<=n;i++)
{
if(helper(s.substring(0,i),wordDict))
dp[i]=true;
else
{
dp[i]=false;
for(int j=i-1;j>=0;j--)
{
if(helper(s.substring(j,i),wordDict)&&dp[j])
{
dp[i]=true;
break;
}
}
}
}
return dp[n];
}
public boolean helper(String s,List<String> wordDict)
{
for(String str:wordDict)
{
if(str.equals(s))
return true;
}
return false;
}
}
标签:equal boolean false bsp 递归 动态规划 int lse n+1
原文地址:https://www.cnblogs.com/cold-windy/p/11494445.html