delete pics to save space

2.10891.cpp

@@ -0,0 +1,39 @@
+#include<cstdio>
+#include<algorithm>
+using namespace std;
+const int maxn=110;
+int n,a[maxn],s[maxn];
+int f[maxn][maxn],g[maxn][maxn],d[maxn][maxn];
+int main()
+{
+#ifdef local
+	freopen("pro.in","r",stdin);
+#endif
+	while(scanf("%d",&n)==1&&n)
+	{
+		s[0]=0;
+		for(int i=1;i<=n;i++) { scanf("%d",&a[i]); s[i]=s[i-1]+a[i]; }
+		for(int i=1;i<=n;i++) f[i][i]=g[i][i]=d[i][i]=a[i];
+		for(int L=1;L<n;L++)
+			for(int i=1;i+L<=n;i++)
+			{
+				int j=i+L;
+				int m=0;
+				m=min(m,f[i+1][j]);
+				m=min(m,g[i][j-1]);
+				d[i][j]=s[j]-s[i-1]-m;
+				f[i][j]=min(d[i][j],f[i+1][j]);
+				g[i][j]=min(d[i][j],g[i][j-1]);
+			}
+		printf("%d\n",2*d[1][n]-s[n]);
+	}
+	return 0;
+}
+/*
+d[1][1]=4
+d[2][2]=-10
+d[3][3]=-20
+d[4][4]=7
+d[1][4]=-6
+
+*/