最长公共子序列

方法1：--------------------------------------------------------------------------------#include<stdio.h>#include<string.h>#include<stdlib.h>#define MAX(a,b)  （ a > b ? a : b）int main(){    int n;    scanf("%d",&n);    while (n--)    {        char a[1000] = {0}, b[1000] = {0};        scanf("%s%s",a,b);        int a_len = strlen(a), b_len = strlen(b);        int dp[a_len+1][b_len+1];      //定义dp[][]用来记录所有可能的最长公共子序列长度        memset(dp, 0, sizeof(dp));    //初始化二维数组dp[][];        int i, j;        for (i = 1; i <= a_len; i++)    //注意i和j应该从一开始        {            for (j = 1; j <= b_len; j++)            {                // 如果a[i-1] == b[i-1],则最长公共子序列长度加1                if (a[i-1] == b[j-1])                    dp[i][j] = dp[i-1][j-1] + 1;                //如果a[i-1] != b[i-1],则在两个子问题中去较大值                else                    dp[i][j] = MAX(dp[i-1][j], dp[i][j-1]);            }        }        printf("%d\n",dp[a_len][b_len]);    }    return 0;}--------------------------------------------------------------------------------方法2：--------------------------------------------------------------------------------#include<stdio.h>#include<string.h>int MAX(int a, int b, int c){    int t = a;    if (t > b)    {        if (t > c)            return a;        else            return c;    }    else    {        if (b > c)            return b;        else            return c;    }}int main(){    int n;    scanf("%d",&n);    while(n--)    {        char a[1000],b[1000];        scanf("%s",a);        scanf("%s",b);        int c[100][100]={0};        memset(c, 0, sizeof(c));        int i,j;        int max=0,same;        for(i=1;i<=strlen(a);i++)            for(j=1;j<=strlen(b);j++)            {                if(a[i-1]==b[j-1])                    same=1;                else                    same=0;                c[i][j]=MAX(c[i-1][j-1]+same,c[i-1][j],c[i][j-1]);                if(max<c[i][j])                    max=c[i][j];            }        printf("%d\n",max);    }    return 0;}--------------------------------------------------------------------------------