Given two words word1 and word2, find the minimum number of steps required to convert word1 to word2. (each operation is counted as 1 step.)
You have the following 3 operations permitted on a word:
a) Insert a character
b) Delete a character
c) Replace a character
解题思路:
又是一道水DP
class Solution {
public:
int minDistance(string word1, string word2) {
int len1 = word1.length();
int len2 = word2.length();
int dp[1010][1010];
memset(dp, 0x3f3f3f3f, sizeof(dp));
dp[0][0] = 0;
for(int i = 1; i <= len1; ++i) {
dp[i][0] = i;
}
for(int i = 1; i <= len2; ++i) {
dp[0][i] = i;
}
for(int i = 1; i <= len1; ++i) {
for(int j = 1; j <= len2; ++j) {
if(word1[i-1] == word2[j-1]) {
dp[i][j] = dp[i-1][j-1];
} else {
dp[i][j] = min(dp[i][j], dp[i-1][j-1] + 1);
dp[i][j] = min(dp[i][j], dp[i][j-1] + 1);
dp[i][j] = min(dp[i][j], dp[i-1][j] + 1);
}
}
}
return dp[len1][len2];
}
};