D.统计子区间乘积 -- dp

 

 

#include <bits/stdc++.h>
using std::cin;
using std::cout;
using i64 = long long;
const int N = 1e5 + 7;
int a[N];
int dp[N],ep[N];
int main(){
    std::ios::sync_with_stdio(false);
    std::cin.tie(nullptr);
    int n;
    cin >> n;
    long long zero = 0,fu = 0,zheng = 0;
    for(int i = 1; i <= n;i++){
        cin >> a[i];
    }
    for(int i = 1; i <= n; i++){
        if(a[i] > 0){
            dp[i] = dp[i - 1] + 1;
            ep[i] = ep[i - 1];
            zheng += dp[i],fu += ep[i];
        }else if(a[i] < 0){
            dp[i] = ep[i - 1];
            ep[i] = dp[i - 1] + 1;
            zheng += dp[i],fu += ep[i];
        }else{
            dp[i] = ep[i] = 0;
        }
        
    }
    zero += (n * 1ll * (n + 1) / 2 - zheng - fu);
    cout << fu << " " << zero << " " << zheng <<"\n";
    return 0;
}