HEU 8004 Human Gene Functions

/**//**************************************
Problem: HEU 8004 Human Gene Functions
Time: 0.0090 s
Memory: 580 k 
Accepted Time: 2009-05-21 14:57:55
Tips: DP http://hi.baidu.com/fandywang_jlu/blog/item/205d37f3c7e2d5c90a46e01a.html
**************************************/
#include <stdio.h>
int table[5][5]={     5,-1,-2,-1,-3,
                    -1, 5,-3,-2,-4,
                    -2,-3, 5,-2,-2,
                    -1,-2,-2, 5,-1,
                    -3,-4,-2,-1, 0};
int main()
{
    int n,i,j;
    int a[109][109];
    char b[10]={"ACGT"};
    scanf("%d",&n);
    while(n--)
    {
        char str1[109],str2[109];
        int len1,len2;
        scanf("%d%s%d%s",&len1,str1+1,&len2,str2+1);
        for(i=1;i<=len1;i++)
        {
            for(j=0;j<4;j++)
            {
                if(str1[i]==b[j])
                {
                    str1[i]=j;
                    break;
                }
            }
        }
        for(i=1;i<=len2;i++)
        {
            for(j=0;j<4;j++)
            {
                if(str2[i]==b[j])
                {
                    str2[i]=j;
                    break;
                }
            }
        }
        for(i=0;i<=len1;i++)
        {
            for(j=0;j<=len2;j++)
            {
                if(i==0&&j==0)a[i][j]=0;
                else if(j==0&&i>0)a[i][j]=a[i-1][j]+table[str1[i]][4];
                else if(i==0&&j>0)a[i][j]=a[i][j-1]+table[str2[j]][4];    
                else
                {
                    a[i][j]=a[i-1][j-1]+table[str1[i]][str2[j]];
                    if(a[i][j]<a[i][j-1]+table[str2[j]][4])a[i][j]=a[i][j-1]+table[str2[j]][4];
                    if(a[i][j]<a[i-1][j]+table[str1[i]][4])a[i][j]=a[i-1][j]+table[str1[i]][4];
                }
            }
        }
        printf("%d\n",a[len1][len2]);
    }
    return 0;
}