显示代码纯文本
#include <iostream>
#include <cstdio>
#include <cstdlib>
using namespace std;
int a[100010],f[2][100010],last[100010];
int main(void)
{
freopen("maxsum.in","r",stdin);
freopen("maxsum.out","w",stdout);
int i,n,sum,maxnum=0,minnum=0,ans,temp;
scanf("%d",&n);
scanf("%d",&a[1]);
sum=a[1];
for (i=2;i<=n;i++)
{
scanf("%d",&a[i]);
sum+=a[i];
if (a[i]*a[i-1]>=0)
{
a[i-1]+=a[i];
i--;
n--;
}
}
for (i=1;i<=n;i++)
{
temp=f[0][i-1]+a[i];
if (temp>0)
f[0][i]=temp;
else
f[0][i]=0;
if (maxnum<f[0][i])
maxnum=f[0][i];
}
for (i=1;i<=n;i++)
{
temp=f[1][i-1]+a[i];
if (temp<0)
f[1][i]=temp;
else
f[1][i]=0;
if (minnum>f[1][i])
minnum=f[1][i];
}
ans=sum-minnum;
if (ans<maxnum)
ans=maxnum;
printf("%d\n",ans);
return(0);
}