九度[1042]-Coincidence

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

解题思路：
动态规划的经典题目：最长公共子序列（LCS）
注意读取的字符串以及对应的长度。

AC代码：

#include <cstdio>#include <cstring>#define max(a,b) a>b?a:b;const int maxn = 110;char dat1[maxn], dat2[maxn];int ans[maxn][maxn];void init(){    for(int i = 0; i < maxn; i++){        for(int j = 0; j < maxn; j++){            ans[i][j] = 0;        }    }}int main(){    freopen("C:\\Users\\Administrator\\Desktop\\test.txt", "r", stdin);    while(scanf("%s%s", dat1+1, dat2+1) != EOF){        init();        int len1 = strlen(dat1+1), len2 = strlen(dat2+1);        int cnt1 = 1, cnt2 = 1;        for(int i = 1; i <= len1; i++){            for(int j = 1; j <= len2; j++){                if(dat1[i] == dat2[j]){                    ans[i][j] = ans[i-1][j-1] + 1;                }                else ans[i][j] = max(ans[i-1][j], ans[i][j-1]);            }        }        printf("%d\n", ans[len1][len2]);    }    fclose(stdin);    return 0;}