动态规划求编辑距离

参考：http://topic.youkuaiyun.com/u/20110607/07/63dec342-b2ec-4f5c-82a8-044531d78392.html

            http://qinxuye.me/article/get-edit-distance-by-dynamic-programming/

//动态规划：
//f[i,j]表示src[0...i]与dst[0...j]的最小编辑距离。
//f[i,j] = min{f[i-1,j]+1, f[i, j-1]+1, f[i-1,j-1]+(src[i]==dst[j]?0:1)}
#include<iostream>
#include<stdlib.h>
#include<stdio.h>
#include<string.h>
using namespace std;

int _Min(int a, int b, int c)
{
	int min = (a > b) ? b : a;
	min = (min > c) ? c : min;

	return min;
}
int CalculateStringDistance(char *src, char *dst)
{
	int n = strlen(src);
	int m = strlen(dst);

	int **d = (int **)malloc((n+1) * sizeof(int *));
	for (int i=0; i <= n; ++i)
	{
		d[i] = (int *)malloc((m+1) * sizeof(int));
	}
	if (n == 0)
	{
		return n;
	}
	if (m == 0)
	{
		return m;
	}
	
	for (int i=0; i <= n; i++)
	{
		d[i][0] = i;
	}
	for (int j=0; j <= m; j++)
	{
		d[0][j] = j;
	}
	for (int i=1; i <=n; ++i)
	{
		for (int j=1; j <=m; j++)
		{
			int cost = (src[i-1] == dst[j-1]) ? 0 : 1;
			d[i][j] = _Min(d[i-1][j] +1, d[i][j-1] + 1, d[i-1][j-1] + cost);
			cout<<"d["<<i<<"]["<<j<<"]"<<" "<<d[i][j]<<" ";
			if (j == m) cout<<endl<<endl;
		}
	}
	return d[n][m];
}

int main(int argc, char *argv[])
{

	char a[10];
	char b[10];
	scanf("%s", &a);
	scanf("%s", &b);

	//char *a = "abc";
	//char *b = "ac";
	int resust = CalculateStringDistance(a, b);
	cout<<resust<<endl;

	return 0;
}