LeetCode 10 Regular Expression Matching

题目

大模拟

c++

class Solution {
public:
    int dp[1005][1005];
    bool ans;
    bool isMatch(string s, string p) {
        
        return judge(s,p,0,0);
    
    }
    bool judge(string s,string p,int i,int j)
{
    if(dp[i][j]==-1)
        return false;
    if(i>=s.length())
    {
        if(j>=p.length())
        {
            return true;
        }
        else{
            if(j==p.length()-1&&p[j]=='*')
            {
                return judge(s,p,i,j+1);
            }
            if(j<=p.length()-2&&p[j+1]=='*')
            {
                return judge(s,p,i,j+2);
            }
            return false;
        }
    }
    if(j>=p.length())
    {
        
        dp[i][j]=-1;
        return false;
        
    }
    if(p[j]=='.')
    {
        ans = judge(s,p,i+1,j+1);
        if(ans==true)
            return true;
        else
        {
            if(j<p.length()-1&&p[j+1]=='*')
            {
                 ans = judge(s,p,i,j+2);
                if(ans==true)
                    return true;
                for(int k=i+1;k<=s.length();k++)
                {
                    ans = judge(s,p,k,j+2);
                    if(ans==true)
                        return true;
                }
            }
            dp[i][j]=-1;
            return false;
        }
    }
    else if(p[j]=='*')
    {
        ans = judge(s,p,i,j+1);
        if(ans==true)
            return true;
        dp[i][j]=-1;
        return false;
    }
    else{
        if(j<p.length()-1&&p[j+1]=='*')
        {
            if(p[j]==s[i])
            {
                ans = judge(s,p,i,j+2);
                if(ans==true)
                    return true;
                for(int k=i+1;k<=s.length();k++)
                {
                    if(p[j]==s[k-1])
                    {
                        ans = judge(s,p,k,j+2);
                        if(ans==true)
                            return true;
                    }
                    else
                        break;
                }
                dp[i][j]=-1;
                return false;
            }
            else
            {
                ans = judge(s,p,i,j+2);
                if(ans==true)
                    return true;
                dp[i][j]=-1;
                return false;
            }
        }
        else
        {
            if(p[j]==s[i])
            {
                ans=judge(s,p,i+1,j+1);
                if(ans==true)
                    return true;
                dp[i][j]=-1;
                return false;
            }
            else
            {
                dp[i][j]=-1;
                return false;
            }
        }
    }
}
    
   
         
};