Submission #68117068

---

Source Code Expand

#include <algorithm>
#include <array>
#include <bitset>
#include <cassert>
#include <chrono>
#include <climits>
#include <cmath>
#include <complex>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <deque>
#include <exception>
#include <fstream>
#include <functional>
#include <iomanip>
#include <iostream>
#include <iterator>
#include <limits>
#include <list>
#include <map>
#include <memory>
#include <new>
#include <numeric>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <stdexcept>
#include <streambuf>
#include <string>
#include <tuple>
#include <typeinfo>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>

using ll = long long;
using ld = long double;
using namespace std;
#define endl "\n";
#define ff first
#define ss second

#define forn(i,n) for(int i=0;i<n;i++)
#define dbgv(v) cout<<#v<<" "<<v<<endl
#define dbga(a,n) forn(i,n-1) {cout<<a[i]<<' ';} cout<<a[n-1]<<'\n';
#define all(v) (v).begin(), (v).end()


const ll N = 1e6 + 5, mod = 1e9 + 7;
ll fact[N], modinv[N];

ll fastpow(ll n, ll m) {
    int ret = 1;
    while (m) {
        if (m & 1)
            (ret *= n) %= mod;
        (n *= n) %= mod;
        m /= 2;
    }
    return ret;
}

void pre() {
    fact[0] = 1;
    for (int i = 1; i < N; i++)
        fact[i] = i * fact[i - 1] % mod;
    modinv[N - 1] = fastpow(fact[N - 1], mod - 2);
    for (int i = N - 2; i >= 0; i--)
        modinv[i] = (i + 1) * modinv[i + 1] % mod;
}

ll ncr(ll n, ll r) {
    return fact[n] * modinv[n - r] % mod * modinv[r] % mod;
}

void dfs(int i,int p, vector<vector<int>>&adj){
	for(auto c:adj[i]){
		dfs(c,i,adj);
	}
}

void solve(){
    ll n;
    cin>>n;
    ll a[n]; 
    forn(i,n){
        cin>>a[i];
    }
    map<ll,ll> v;
    ll ans=0;
    forn(i,n){
        ans+=v[(a[i]-i)];
        v[-i-a[i]]++;
    }
    cout<<ans<<endl;
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(0);

    int T = 1;
    // cin >> T;
    while(T--){
        solve();
    }
    return 0;
}

Submission Info

Compile Error

Main.cpp: In function ‘void dfs(int, int, std::vector<std::vector<int> >&)’:
Main.cpp:79:20: warning: unused parameter ‘p’ [-Wunused-parameter]
   79 | void dfs(int i,int p, vector<vector<int>>&adj){
      |                ~~~~^

Judge Result