delete pics to save space

history_source/信息学奥赛一本通/2.6.2.cpp

@@ -0,0 +1,28 @@
+#include<cstdio>
+int n,a[105][105],s[105][105],y[105],max,maxn,i,j,l,r,ans;
+inline int Max(int a,int b){return a>b?a:b;}
+int answer()
+{
+	for(j=1;j<=n;j++) y[j]=s[j][r]-s[j][l-1];
+	max=maxn=y[1];
+	for(j=2;j<=n;j++)
+	{
+		if(maxn<0) maxn=y[j];
+		else maxn+=y[j];
+		max=Max(max,maxn);
+	}
+	return max;
+}
+int main()
+{
+	scanf("%d",&n);
+	for(i=1;i<=n;i++)
+		for(j=1;j<=n;j++) scanf("%d",&(a[j][i]));
+	for(j=1;j<=n;j++)
+		for(i=1;i<=n;i++) s[j][i]=s[j][i-1]+a[j][i];
+	ans=a[1][1];
+	for(l=1;l<=n;l++)
+		for(r=l;r<=n;r++) ans=Max(ans,answer());
+	printf("%d\n",ans);
+	return 0;
+}