1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
#include <bits/stdc++.h>

using namespace std;

#define FOR(i, l, r) for(int i = (l); i <= (r); ++i)
#define REP(i, n) FOR(i, 0, (n) - 1)
#define rep(i, a, b) for(int i = a; i < (b); ++i)

#define all(x) x.begin(), x.end()
#define sz(x) (int)(x).size()
#define ssize(x) int(x.size())

#define pb push_back
#define fi first
#define se second
#define ld long double

typedef long long ll;
typedef vector<int> vi;
typedef pair<int, int> pii;
typedef pair <ld, ld> pd;

using LL=long long;

#ifdef DEBUG
auto &operator<<(auto &o, pair<auto, auto> p) {
    return o << "()" << p.first << ", " << p.second <<")";
}
auto operator<<(auto &o, auto x)-> decltype(x.end(), o) {
    o << "{";int i = 0;
    for(auto e : x) o << ", "+!i++<<e;
    return o <<"}";
}
#define debug(x...) cerr << "["#x"]: ",[](auto...$){((cerr<<$<<"; "),...)<<endl;}(x)
#else
#define debug(...) {}
#endif

void solve() {
    int N;
    cin >> N;

    vector<int> a(N);
    REP(i, N) cin >> a[i];

    vector<int> S;

    for (int i = 0; i < N; i++) {
        int cur_sum = 0;

        for (int j = i; j < N; j++) {
            cur_sum += a[j];
            S.pb(cur_sum);
        }
    }
    
    ll cnt = 0;
    N = S.size();
    sort(all(S));   

    map<int, int> counter;

    for (int i = 0; i < N - 1; i++) {
        int current = S[i];
        
        for (int j = i + 1; j < N; j++) {
            cnt += (ll)counter[-(current + S[j])];
            counter[S[j]] += 1;
        }

        counter.clear();
    }

    cout << cnt << '\n';
}

signed main() {
    cin.tie(0)->sync_with_stdio(0);

    int t = 1;
    // cin >> t;
    while(t--) {
        solve();
    }
}