题目1042：Coincidence

题目1042：Coincidence

时间限制：1 秒

内存限制：32 兆

特殊判题：否

提交：3744

解决：2049

题目描述：

Find a longest common subsequence of two strings.

输入：

First and second line of each input case contain two strings of lowercase character a…z. There are no spaces before, inside or after the strings. Lengths of strings do not exceed 100.

输出：

For each case, output k – the length of a longest common subsequence in one line.

样例输入：

abcd
cxbydz

样例输出：

2

#include <iostream>
#include <cstring>
#include <stdio.h>
using namespace std;

int dp[105][105];
char a[105];
char b[105];

int max(int x,int y){
	if(x>=y)
		return x;
	else 
		return y;
}

int main(){
	while(scanf("%s %s",&a,&b)!=EOF){
		int lena=strlen(a);
		int lenb=strlen(b);
		for(int i=0;i<=lena;i++)  //这里其实扩了一圈0
			dp[i][0]=0;
		for(int j=0;j<=lenb;j++)
			dp[0][j]=0;
		for(int i=1;i<=lena;i++){
			for(int j=1;j<=lenb;j++){
				if(a[i-1]==b[j-1])
					dp[i][j]=dp[i-1][j-1]+1;
				else
					dp[i][j]=max(dp[i-1][j],dp[i][j-1]);
			}
		}
		cout<<dp[lena][lenb]<<endl;
	}
	return 0;
}