class Solution {
public:
int minDistance(string s1, string s2) {
int n = s1.size() , m = s2.size();
vector<vector<int>> dp(n+1,vector<int>(m+1,1e9));
dp[0][0] = 0;
for(int i=0;i<=n;i++){
dp[i][0] = i;
}
for(int i=0;i<=m;i++){
dp[0][i] = i;
}
for(int i=1;i<=n;i++){
for(int j=1;j<=m;j++){
if(s1[i-1]==s2[j-1]){
dp[i][j] = min(dp[i][j],dp[i-1][j-1]);
}else{
dp[i][j] = min(dp[i-1][j],dp[i][j-1])+1;
}
}
}
return dp[n][m];
}
};
当然也可直接处理成LCS的问题
class Solution {
public:
int minDistance(string word1, string word2) {
int len = longestCommonSubsequence(word1,word2);
return word1.size()+word2.size()-2*len;
}
int longestCommonSubsequence(string s1, string s2) {
int n = s1.size() , m = s2.size();
vector<vector<int>> dp(n+1,vector<int>(m+1,0));
for(int i=1;i<=n;i++){
for(int j=1;j<=m;j++){
dp[i][j] =max(dp[i-1][j-1]+(s1[i-1]==s2[j-1]),max(dp[i][j-1],dp[i-1][j]));
}
}
return dp[n][m];
}
};