第六章部分例题

#include <iostream>
#include <cstdio>
#include <cstring>

using namespace std;

int const maxn=10000;
int sum[maxn];


void built(int p)
{
    int v;
    cin>>v;

    if(v==-1) return;

    sum[p]+=v;
    built(p-1);
    built(p+1);
}

bool init()
{
    memset(sum,0,sizeof(sum));

    int v;
    cin>>v;
    if (v==-1) return false;

    int p=maxn/2;
    sum[p]=v;

    built(p-1);
    built(p+1);

    return true;
}

int main()
{
    while(init())
    {
        int p=0;

        while(sum[p]==0) p++;

        cout<<sum[p];

        while(sum[++p]!=0) cout<<" "<<sum[p];

        cout<<endl;
    }

    return 0;
}