ZOJ 2059 The Twin Towers

#include<cstdio>
#include<cstring>
#include<cmath>
#include<algorithm>
using namespace std;

int dp[105][4000 + 10];
int a[105];
int n, sum;

void read()
{
for (int i = 1; i <= n; i++) scanf("%d", &a[i]);
}

void work()
{
sum = 0;
for (int i = 1; i <= n; i++) sum = sum + a[i];
memset(dp, -1, sizeof dp);
int h; h = a[1];
dp[1][h + sum] = dp[1][0 - h + sum] = dp[1][sum] = 0;
for (int i = 2; i <= n; i++)
{
h = a[i];
for (int j = 0; j <= sum*2; j++) dp[i][j] = dp[i - 1][j];
for (int j = 0; j <= sum*2; j++)
{
if (dp[i - 1][j] == -1) continue;

int tmp = j - sum;
if (tmp >= 0)
{
dp[i][h + tmp + sum] = max(dp[i][h + tmp + sum], dp[i - 1][j]);
dp[i][tmp - h + sum] = max(dp[i][tmp - h + sum], dp[i - 1][j] + min(tmp, h));
}
else if (tmp<0)
{
tmp = -tmp;
dp[i][0 - (tmp + h) + sum] = max(dp[i][0 - (tmp + h) + sum], dp[i - 1][j]);
dp[i][h - tmp + sum] = max(dp[i][h - tmp + sum], dp[i - 1][j] + min(tmp, h));
}
}
}
int ans = 0;
for (int i = 1; i <= n; i++) ans = max(ans, dp[i][sum]);
if (ans == 0) printf("Sorry\n");
else printf("%d\n", ans);
}

int main()
{
while (~scanf("%d", &n))
{
read();
if (n < 0) break;
if (n <=1) printf("Sorry\n");
else work();
}
return 0;
}