UVA 1182 - Sequence Alignment solution

#include<bits/stdc++.h>
using namespace std;

#define inf -123456789

int visited=1,n,m,t,ans;
string s1,s2;
int dp[51][51][2][2],vis[51][51][2][2];

void ready()
{
    //freopen("f.txt","r",stdin);
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
}

int call(int i,int j,int a,int b)
{
    if(i==n&&j==m)
        return 0;
    if(vis[i][j][a][b]==visited)
        return dp[i][j][a][b];
    dp[i][j][a][b]=inf;
    vis[i][j][a][b]=visited;
    if(i<n&&j<m)
    {
        if(s1[i]==s2[j])
            dp[i][j][a][b]=max(dp[i][j][a][b],2+call(i+1,j+1,1,1));
        dp[i][j][a][b]=max(dp[i][j][a][b],call(i+1,j+1,1,1));
    }
    if(i<n)
        dp[i][j][a][b]=max(dp[i][j][a][b],call(i+1,j,1,0)-(b==1));
    if(j<m)
        dp[i][j][a][b]=max(dp[i][j][a][b],call(i,j+1,0,1)-(a==1));
    return dp[i][j][a][b];
}

int main()
{
    ready();
    cin>>t;
    while(t--)
    {
        cin>>s1>>s2;
        n=s1.size();
        m=s2.size();
        ans=inf;
        for(int i=0;i<n;i++)
            ans=max(ans,call(i,0,1,1));
        for(int i=0;i<m;i++)
            ans=max(ans,call(0,i,1,1));
        cout<<ans<<endl;
        visited++;
    }
    return 0;
}


/*

2
AADDEFGGHC
ADCDEGH
ERTTHCBYNQC
BEARTBCHQYN

*/