POJ 2385

#include <algorithm>
#include <cstdlib>
#include <numeric>
#include <iostream>
using namespace std;

int max(int i,int j)
{
    if(i > j)
        return i;
    return j;
}

int main() 
{
    //freopen("acm.acm","r",stdin);
    int dp[1005][31];
    int tree[1005];
    int T;
    int W;
    int i;
    int j;
    memset(dp,0,sizeof(dp));
    cin>>T>>W;
    for(i = 1;i <= T; ++ i)
        cin>>tree[i];
    for(i = 1; i <= T; ++ i)
    {
        dp[i][0] = dp[i-1][0];
        if(tree[i] == 1)
           ++ dp[i][0];
    }
    for(i = 1;i <= T;++ i)
    {
        for(j = 1;j <= W;++ j)
        {
            if(j > i)
                break;
            dp[i][j] = max(dp[i-1][j],dp[i-1][j-1]);
            if(tree[i] == j%2+1)
                ++ dp[i][j];
        }
    }
    cout<<dp[T][W];
    return 0;
}