delete pics to save space

history_source/信息学奥赛一本通/2.9.3.9.cpp

@@ -0,0 +1,40 @@
+#include<cstdio>
+#include<cstring>
+#include<algorithm>
+using namespace std;
+int n,a[50005],dp[3][50005];
+void solve()
+{
+	memset(dp,0,sizeof(dp));
+	scanf("%d",&n);
+	for(int i=1;i<=n;i++) scanf("%d",a+i);
+	dp[1][1]=a[1];
+	dp[2][1]=dp[2][0]=-500000005;
+	int max1=a[1],res;
+	for(int i=2;i<=n;i++)
+	{
+		dp[1][i]=max(a[i],dp[1][i-1]+a[i]);
+		dp[2][i]=max(max1+a[i],dp[2][i-1]+a[i]);
+		max1=max(max1,dp[1][i]);
+	}
+//	for(int i=1;i<=n;i++) printf("%11d%11d\n",dp[1][i],dp[2][i]); 
+	res=dp[2][1];
+	for(int i=2;i<=n;i++) res=max(res,dp[2][i]);
+	printf("%d\n",res);
+}
+int main()
+{
+	int t;
+	scanf("%d",&t);
+	while(t-->0) solve();
+	return 0;
+}
+/*
+1
+10
+1 -1 2 2 3 -3 4 -4 5 -5
+
+1
+10
+-4 -5 -6 -7 -8 -9 -10 -1 -2 -3
+*/