#include<bits/stdc++.h>
#define FOR(i,a,b) for(int i=a;i<b;++i)
#define FORD(i,a,b) for(int i=a;i>=b;--i)
#define PB push_back
#define EB emplace_back
#define FI first
#define SE second
#define umap unordered_map
#define uset unordered_set
#define vi vector<int>
#define vvi vector<vi>
#define vll vector<ll>
#define vvll vector<vll>
#define vpii vector<pii>
#define pii pair<int, int>
#define pll pair<ll, ll>
#define ALL(X) (X).begin(),(X).end()
#ifndef DEBUG
#define endl (char)10
#endif
using namespace std;
using ll = long long;
using ld = long double;
template <class T>
ostream& operator<< (ostream& os, const vector<T>& vec){
for(auto& t : vec) os << t << " ";
return os;
}
template<class T, class U>
ostream& operator<< (ostream& os, const pair<T, U>& p){
os << p.FI << " " << p.SE;
return os;
}
template<class T, class U>
istream& operator>> (istream& is, pair<T, U>& p){
is >> p.FI >> p.SE;
return is;
}
template <class T>
istream& operator>> (istream& is, vector<T>& vec){
for(auto& p : vec) is >> p;
return is;
}
int main () {
ios_base::sync_with_stdio(false);
cin.tie(0);
int n;
cin >> n;
vi V(n);
cin >> V;
ll s = 0;
for(int x : V) s += x;
vi divs;
if(s <= n) divs.PB(s);
ll t = 2;
while(t * t < s) {
if (s % t == 0) {
if (t <= n) divs.PB(t);
if (s / t <= n) divs.PB(s / t);
}
t++;
}
if (t * t == s && t <= n) divs.PB(t);
random_shuffle(ALL(divs));
vi can(divs.size(), 0);
int ans = 1;
vi eventy(n + 1, 0);
FOR(i2,0,divs.size()){
assert(divs[i2] != 0);
int cand = divs[i2];
assert(cand <= n);
bool ok2 = true;
FOR(i,0,i2) {
if (can[i] == 0 && cand % divs[i] == 0) {
ok2 = false;
break;
}
if (can[i] == 1 && divs[i] % cand == 0){
ok2 = false;
can[i2] = 1;
break;
}
}
if (!ok2) continue;
//cout << i2 << " start" << endl;
int s2 = 0;
//cout << "cand " << cand << endl;
can[i2] = 1;
eventy.assign(n + 1, 0);
FOR(i,0,n){
assert(s2 >= 0);
//cout << "it " << i << ": " << eventy << endl;
s2 += eventy[i];
//cout << "BEF " << i << " " << s2 << endl;
if (s2 > V[i] || (s2 < V[i] && i + cand > n)){
can[i2] = 0;
break;
}
if (s2 != V[i]) {
int pom = s2 - V[i];
s2 = V[i];
eventy[i + cand] = pom;
}
//cout << i << " " << s2 << endl;
}
if (can[i2] == 1) ans = max(ans, divs[i2]);
//cout << i2 << " 0k" << endl;
}
//cout << divs << endl << can << endl;
//cout << "blosssom" << endl;
cout << ans << endl;
}
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 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 | #include<bits/stdc++.h> #define FOR(i,a,b) for(int i=a;i<b;++i) #define FORD(i,a,b) for(int i=a;i>=b;--i) #define PB push_back #define EB emplace_back #define FI first #define SE second #define umap unordered_map #define uset unordered_set #define vi vector<int> #define vvi vector<vi> #define vll vector<ll> #define vvll vector<vll> #define vpii vector<pii> #define pii pair<int, int> #define pll pair<ll, ll> #define ALL(X) (X).begin(),(X).end() #ifndef DEBUG #define endl (char)10 #endif using namespace std; using ll = long long; using ld = long double; template <class T> ostream& operator<< (ostream& os, const vector<T>& vec){ for(auto& t : vec) os << t << " "; return os; } template<class T, class U> ostream& operator<< (ostream& os, const pair<T, U>& p){ os << p.FI << " " << p.SE; return os; } template<class T, class U> istream& operator>> (istream& is, pair<T, U>& p){ is >> p.FI >> p.SE; return is; } template <class T> istream& operator>> (istream& is, vector<T>& vec){ for(auto& p : vec) is >> p; return is; } int main () { ios_base::sync_with_stdio(false); cin.tie(0); int n; cin >> n; vi V(n); cin >> V; ll s = 0; for(int x : V) s += x; vi divs; if(s <= n) divs.PB(s); ll t = 2; while(t * t < s) { if (s % t == 0) { if (t <= n) divs.PB(t); if (s / t <= n) divs.PB(s / t); } t++; } if (t * t == s && t <= n) divs.PB(t); random_shuffle(ALL(divs)); vi can(divs.size(), 0); int ans = 1; vi eventy(n + 1, 0); FOR(i2,0,divs.size()){ assert(divs[i2] != 0); int cand = divs[i2]; assert(cand <= n); bool ok2 = true; FOR(i,0,i2) { if (can[i] == 0 && cand % divs[i] == 0) { ok2 = false; break; } if (can[i] == 1 && divs[i] % cand == 0){ ok2 = false; can[i2] = 1; break; } } if (!ok2) continue; //cout << i2 << " start" << endl; int s2 = 0; //cout << "cand " << cand << endl; can[i2] = 1; eventy.assign(n + 1, 0); FOR(i,0,n){ assert(s2 >= 0); //cout << "it " << i << ": " << eventy << endl; s2 += eventy[i]; //cout << "BEF " << i << " " << s2 << endl; if (s2 > V[i] || (s2 < V[i] && i + cand > n)){ can[i2] = 0; break; } if (s2 != V[i]) { int pom = s2 - V[i]; s2 = V[i]; eventy[i + cand] = pom; } //cout << i << " " << s2 << endl; } if (can[i2] == 1) ans = max(ans, divs[i2]); //cout << i2 << " 0k" << endl; } //cout << divs << endl << can << endl; //cout << "blosssom" << endl; cout << ans << endl; } |
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