编辑距离(附带操作)

package N02;

public class Solution {

	class Node{
		int value;
		//选择
		//0表示啥都不做，1表示插入，2表示删除，3表示替换
		int choice;
		
		Node(int value, int choice){
			this.value = value;
			this.choice = choice;
		}
	}
	
	public int minDistance(String str1, String str2) {
		int m = str1.length();
		int n = str2.length();
		Node[][] dp = new Node[m + 1][n + 1];
		//初始化基础情况
		for(int i = 0; i <= m; i ++) {
			dp[i][0] = new Node(i, 2); //删除
		}
		for(int j = 1; j <= n; j ++) {
			dp[0][j] = new Node(j, 1);
		}
		for(int i = 1; i <= m; i ++) {
			for(int j = 1; j <= n; j ++) {
				if(str1.charAt(i - 1) == str2.charAt(j - 1)) {
					dp[i][j] = new Node(dp[i - 1][j - 1].value, 0); 
				}else {
					dp[i][j] = minNode(dp[i - 1][j], dp[i - 1][j - 1], dp[i][j - 1]);
					dp[i][j].value ++;
				}
				
			}
		}
		
		//展示最后的结果
		printResult(dp, str1, str2);
		return dp[m][n].value;
	}
	
	//a表示删除，b表示替换，c表示添加
	private Node minNode(Node a, Node b, Node c) {
		Node res = new Node(a.value, 2);
		
		if(res.value > b.value) {
			res.value = b.value;
			res.choice = 3;
			
		}
		
		if(res.value > c.value) {
			res.value = c.value;
			res.choice = 1;
		}
		
		return res;
	}
	
	
	//展示最后的结果
	//这里的dp表示的是操作，str1，str2表示的是数据
	private void printResult(Node[][] dp, String str1, String str2) {
		int rows = dp.length;
		int cols = dp[0].length;
		
		int i = rows - 1, j = cols - 1;//标识位
		System.out.println("从" + str1 + "到" + str2 + "的最短编辑距离为：");
		
		while(i != 0 && j != 0) {
			char c1 = str1.charAt(i - 1);
			char c2 = str2.charAt(j - 1);
			int choice = dp[i][j].choice;
			//每次都要打印
			System.out.print("s1[" + (i - 1) + "]");
			switch(choice) {
			case 0:
				System.out.println("跳过'" + c1 + "'");
				//移动游标
				i --;
				j --;
				break;
			case 1:
				System.out.println("插入'" + c2 + "'");
				j --;
				break;
			case 2:
				System.out.println("删除'" + c1 + "'");
				i --;
				break;
			case 3:
				System.out.println("替换'" + c1 + "'" + "为'" + c2 + "'");
				i --;
				j --;
				break;
			}
		}
		
		while(i > 0) {
			System.out.print("s1[" + (i - 1) + "]");
			System.out.println("删除'" + str1.charAt(i - 1) + "'");
			i --;
		}
		while(j > 0){
			System.out.print("s1[" + (i - 1) + "]");
			System.out.println("添加'" + str2.charAt(j - 1) + "'");
			j --;
		}
	}
}

标签：Node,附带,System,value,编辑,int,距离,dp,out
来源： https://blog.csdn.net/qq_44652489/article/details/120623338