ZOJ 3331 Process the Tasks

双塔DP。

#include<cstdio>
#include<cstring>
#include<queue>
#include<string>
#include<algorithm>
#include<map>
#include<iostream>
using namespace std;

const int maxn=+;
int T,n;
int dp[maxn][*maxn];
int a[maxn],b[maxn];

void init()
{
    for(int i=;i<=n;i++)
        for(int j=;j<=;j++)
            dp[i][j]=0x7fffffff;
}

void read()
{
    scanf("%d",&n);
    for(int i=;i<=n;i++) scanf("%d%d",&a[i],&b[i]);
}

void work()
{
    dp[][a[]+]=dp[][-b[]+]=;

    for(int i=;i<=n;i++)
    {
        for(int j=;j<=;j++)
        {
            if(dp[i-][j]==0x7fffffff) continue;
            int tmp=j-;
            if(tmp>=)
            {
                dp[i][a[i]+]=min(dp[i][a[i]+],dp[i-][j]+tmp);
                if(b[i]>=tmp) dp[i][tmp-b[i]+]=min(dp[i][tmp-b[i]+],dp[i-][j]+tmp);
                else if(b[i]<tmp) dp[i][tmp-b[i]+]=min(dp[i][tmp-b[i]+],dp[i-][j]+b[i]);
            }

            else if(tmp<)
            {
                tmp=-tmp;
                if(dp[i-][j]+tmp<dp[i][-b[i]+]) dp[i][-b[i]+]=min(dp[i][-b[i]+],dp[i-][j]+tmp);
                if(a[i]<=tmp) dp[i][a[i]-tmp+]=min(dp[i][a[i]-tmp+],dp[i-][j]+a[i]);
                else if(a[i]>tmp) dp[i][a[i]-tmp+]=min(dp[i][a[i]-tmp+],dp[i-][j]+tmp);
            }
        }
    }

    int ans=0x7fffffff;
    for(int j=;j<=;j++)
    {
        if(dp[n][j]==0x7fffffff) continue;
        ans=min(ans,dp[n][j]+abs(j-));
    }
    printf("%d\n",ans);
}

int main()
{
    scanf("%d",&T);
    while(T--)
    {
        read();
        init();
        work();
    }
    return ;
}