Description:
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:
Insert a characterDelete a characterReplace a character
Example
Given word1 = "mart" and word2 = "karma", return 3.
Solution:
class Solution {
public:
/**
* @param word1 & word2: Two string.
* @return: The minimum number of steps.
*/
int minDistance(string word1, string word2) {
auto len1 = (int)word1.length();
auto len2 = (int)word2.length();
if (len1 == 0) return len2;
if (len2 == 0) return len1;
vector<int> pre(len2+1, 0);
vector<int> cur(len2+1, 0);
for (int i = 0; i <= len2; ++i) pre[i] = i;
for (int i = 1; i <= len1; ++i) {
cur[0] = i;
for (int j = 1; j <= len2; ++j) {
if (word1[i-1] == word2[j-1]) cur[j] = pre[j-1];
else cur[j] = min(cur[j-1], min(pre[j], pre[j-1]))+1;
pre[j-1] = cur[j-1];
}
pre[len2] = cur[len2];
}
return cur[len2];
}
};
转载于:https://www.cnblogs.com/deofly/p/edit-distance.html
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