Problem - 1118B - Codeforces(Tanya and Candies)

记录奇数和和偶数和。

然后搞一下就可以了

 1 #include <iostream>
 2 #include <cstring>
 3 #include <string>
 4 #include <map>
 5 #include <set>
 6 #include <algorithm>
 7 #include <fstream>
 8 #include <cstdio>
 9 #include <cmath>
10 #include <stack>
11 #include <queue>
12 using namespace std;
13 const double Pi=3.14159265358979323846;
14 typedef long long ll;
15 const int MAXN=300000+5;
16 const int dx[5]={0,0,0,1,-1};
17 const int dy[5]={1,-1,0,0,0};
18 const int INF = 0x3f3f3f3f;
19 const int NINF = 0xc0c0c0c0;
20 const ll mod=1e9+7;
21 int a[MAXN];
22 ll even[MAXN];
23 ll odd[MAXN];
24 int main()
25 {
26     int n;cin>>n;
27     for(int i=1;i<=n;i++)
28     {
29         scanf("%d",&a[i]);
30         if(i%2) 
31         {
32             odd[i]=odd[i-1]+a[i];
33             even[i]=even[i-1];
34         }
35         else 
36         {
37             even[i]=even[i-1]+a[i];
38             odd[i]=odd[i-1];
39         }
40     }
41     int ans=0;
42     for(int i=1;i<=n;i++)
43     {
44         ll qi,o;
45         qi=odd[i-1]+even[n]-even[i];
46         o=even[i-1]+odd[n]-odd[i];
47         if(qi==o) 
48         {
49             ans++;
50         }
51     }
52     cout <<ans<<endl;
53     
54     return 0;
55 }