delete pics to save space

history_source/信息学奥赛一本通/2.9.3.6.cpp

@@ -0,0 +1,40 @@
+#include<cstdio>
+#include<cstring>
+#define min(a,b) ((a)<(b)?(a):(b))
+#define max(a,b) ((a)>(b)?(a):(b))
+#define INT_MAX 10000000
+int i,t,n,ans,maxprice,minprice;
+int a[100005],dp1[100005],dp2[100005]; 
+void read(int &x) 
+{
+	int f=1;x=0;
+	char c=getchar();
+	for (;!(c>='0'&&c<='9');c=getchar()) if(c=='-') f=-1;
+	for (;c>='0'&&c<='9';c=getchar()) x=x*10+c-'0';
+	x*=f;
+}
+int main() 
+{
+	read(t);
+	while (t--) 
+	{
+		memset(dp1,0,sizeof(dp1));
+		memset(dp2,0,sizeof(dp2));
+		ans=0; minprice=INT_MAX; read(n);
+		for (i=1;i<=n;i++) read(a[i]);
+		for (i=1;i<=n;i++) 
+		{
+			minprice=min(minprice,a[i]);
+			dp1[i]=max(dp1[i-1],a[i]-minprice);
+		}
+		maxprice=-INT_MAX;
+		for (i=n;i>=1;i--)
+		{
+			maxprice=max(maxprice,a[i]);
+			dp2[i]=max(dp2[i+1],maxprice-a[i]);
+		}
+		for (i=1;i<=n;i++) ans=max(ans,dp1[i]+dp2[i+1]);
+		printf("%d\n",ans);
+	}
+	return 0;
+}