delete pics to save space

history_source/ccf 基础篇/U7/7.6.3.cpp

@@ -0,0 +1,32 @@
+#include<cstdio>
+int n,a[305][305],y[305][305],maxn,max,i,j,k;
+int main()
+{
+	scanf("%d",&n);
+	for(i=0;i<n;i++)
+		for(j=0;j<n;j++)
+			scanf("%d",&(a[j][i]));
+	for(i=0;i<n;i++)
+		for(j=1;j<=n;j++)
+			y[i][j]=y[i][j-1]+a[i][j-1];
+	for(i=1;i<=n;i++)
+		for(j=i;j<=n;j++)
+		{
+			maxn=0;
+			for(k=0;k<n;k++)
+			{
+				if(maxn<0) maxn=y[k][j]-y[k][i-1];
+				else maxn+=y[k][j]-y[k][i-1];
+				if(maxn>max) max=maxn;
+			}
+		}
+	printf("%d\n",max);
+	return 0;
+}
+/*
+4
+0 -2 -7 0 
+9 2 -6 2
+-4 1 -4 2
+-1 8 0 -2
+*/