Codeforces Round #690 (Div. 3) D. Add to Neighbour and Remove
- Time : O(nlogn)
- Space : O(n)
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| #include <bits/stdc++.h>
#pragma optimization_level 3 #pragma GCC optimize("Ofast,no-stack-protector,unroll-loops,fast-math,O3") #pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx") #pragma GCC optimize("Ofast") #pragma GCC target("avx,avx2,fma") #pragma GCC optimization ("unroll-loops")
struct PairHash {inline std::size_t operator()(const std::pair<int,int> & v) const {return v.first*31+v.second;}};
#define MAX_N 202020 #define INF 987654321 #define EPS 1e-9 #define ll long long #define pll pair<ll, ll> #define vpll vector<pll> #define vall3 vector<array<ll,3>> #define all3 array<ll,3> #define all5 array<ll,5> #define vall5 vector<all5> #define vll vector<ll> #define vi vector<int> #define vs vector<string> #define usll unordered_set<ll> #define uspll unordered_set<pll, PairHash> #define umll unordered_map<ll,ll> #define vvs vector<vs> #define vvll vector<vll> #define all(a) begin(a), end(a) #define rall(a) rbegin(a), rend(a)
using namespace std; ll solve(vll& A) { ll n = A.size(), sum = 0; usll us; for(ll i = 0; i < n; i++) { sum += A[i]; us.insert(sum); } for(ll i = n; i >= 1; i--) { if(sum % i != 0) continue; ll div = sum / i; bool f = true; for(ll j = div; j <= sum and f; j += div) { if(!us.count(j)) f = false; } if(f) return n - i; } return -1; }
int main() { ios_base::sync_with_stdio(0); cin.tie(0); ll tc = 1; cin>>tc; for(ll i = 1; i <= tc; i++) { ll n; cin>>n; vll A(n); for(ll j = 0; j < n; j++) cin>>A[j]; cout<<solve(A)<<endl; } return 0; }
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