MinED.java

package com.lamoop.competition;


public class MinED {
	public int editDistance(String str1, String str2) {
		// 计算两个字符串的长度。
		int len1 = str1.length();
		int len2 = str2.length();
		// 建立上面说的数组，比字符长度大一个空间
		int[][] dif = new int[len1 + 1][len2 + 1];
		// 赋初值，步骤B。
		for (int a = 0; a <= len1; a++) {
			dif[a][0] = a;
		}
		for (int a = 0; a <= len2; a++) {
			dif[0][a] = a;
		}
		// 计算两个字符是否一样，计算左上的值
		int temp;
		for (int i = 1; i <= len1; i++) {
			for (int j = 1; j <= len2; j++) {
				if (str1.charAt(i - 1) == str2.charAt(j - 1)) {
					temp = 0;
				} else {
					temp = 1;
				}
				// 取三个值中最小的
				dif[i][j] = min(dif[i - 1][j - 1] + temp, dif[i][j - 1] + 1,
						dif[i - 1][j] + 1);
			}
		}
		return dif[len1][len2];
	}

	private int min(int... is) {
		int min = Integer.MAX_VALUE;
		for (int i : is) {
			if (min > i) {
				min = i;
			}
		}
		return min;
	}

}