View Code of Problem 1011

#include<cstdio>
#include<cstring>
#include<algorithm>
using namespace std;
int dp[50][1050],pr[50][1050];
const int inf=0x3f3f3f3f;
void dfs(int k,int d)
{
    if(pr[k][d]!=-1)
    {
        dfs(k-1,pr[k][d]);
        printf("%c",(pr[k][d]>d)?'D':'U');
    }
}
int main()
{
    int T;
    for(scanf("%d",&T);T;T--)
    {
        int n;
        scanf("%d",&n);
        memset(dp,0x3f,sizeof(dp));
        memset(pr,-1,sizeof(pr));
        dp[0][0]=0;
        for(int i=1,d;i<=n;i++)
        {
            scanf("%d",&d);
            for(int j=0;j<=1000;j++)
            {
                if(j-d>=0&&dp[i-1][j-d]!=inf&&dp[i][j]>max(dp[i-1][j-d],j))
                {
                    dp[i][j]=max(dp[i-1][j-d],j);
                    pr[i][j]=j-d;
                }
                if(j+d<=1000&&dp[i-1][j+d]!=inf&&dp[i][j]>dp[i-1][j+d])
                {
                    dp[i][j]=dp[i-1][j+d];
                    pr[i][j]=j+d;
                }
            }
        }
        if(dp[n][0]==inf)
            printf("IMPOSSIBLE");
        else
            dfs(n,0);
        printf("\n");
    }
    return 0;
}