#include<bits/stdc++.h>
#define VAR(i,n) __typeof(n) i = (n)
#define loop(i,j,s) for(int i=j;i<s;i++)
#define loopback(i,j,s) for(int i=j;i>=s;i--)
#define foreach(i,c) for(VAR(i,(c).begin());i!=(c).end();i++)
#define pln( x ) cout << x << "\n"
#define ps( x ) cout << x << " "
#define entr cout << "\n"
#define pcnt(i) __builtin_popcount(i)
#define ll long long
#define pb push_back
#define mp make_pair
#define ff first
#define ss second
#define SIZE(c) (c).size()
#define ALL(c) (c).begin(), (c).end()
using namespace std;
typedef vector<int> VI;
typedef pair<int, int> PII;
typedef vector<vector<int> > VVI;
const int INFTY=20000000;
const int MAX=100100;
const int MOD=10000000;
void coutTab(int* tab,int n){
loop(i,0,n){
cout<<tab[i]<<" ";
}
cout<<"\n";
}
template<class T> void coutVec(vector<T> tab){
for(T t : tab){
cout<<t<<" ";
}
cout<<"\n";
}
//------------------------------------------
int n;
int a[MAX];
int b[MAX];
bool check(int k) {
if(k==1) return true;
loop(i,0,n) b[i]=0;
int f=a[0];
b[0]=a[0];
loop(i,1,n) {
// ps(a[i]);ps(f);
if(i-k>=0) f-=b[i-k];
if(a[i]<f) return false;
b[i]=a[i]-f;
// ps(b[i]);
f+=b[i];
// pln(f);
}
return f==b[n-k];
}
int findK() {
int s=1;
int e=n;
while(s<e) {
int m=(s+e+1)/2;
if(check(m)) {
s=m;
} else {
e=m-1;
}
}
return s;
}
int main(){
ios_base::sync_with_stdio(0);
cin>>n;
ll S=0;
loop(i,0,n) { cin>>a[i]; S += (ll) a[i]; }
int maxi=1;
// pln(S);
loop(i,2,n+1) {
if(S%i==0 && check(i))
maxi = max(maxi,i);
}
pln(maxi);
}
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 | #include<bits/stdc++.h> #define VAR(i,n) __typeof(n) i = (n) #define loop(i,j,s) for(int i=j;i<s;i++) #define loopback(i,j,s) for(int i=j;i>=s;i--) #define foreach(i,c) for(VAR(i,(c).begin());i!=(c).end();i++) #define pln( x ) cout << x << "\n" #define ps( x ) cout << x << " " #define entr cout << "\n" #define pcnt(i) __builtin_popcount(i) #define ll long long #define pb push_back #define mp make_pair #define ff first #define ss second #define SIZE(c) (c).size() #define ALL(c) (c).begin(), (c).end() using namespace std; typedef vector<int> VI; typedef pair<int, int> PII; typedef vector<vector<int> > VVI; const int INFTY=20000000; const int MAX=100100; const int MOD=10000000; void coutTab(int* tab,int n){ loop(i,0,n){ cout<<tab[i]<<" "; } cout<<"\n"; } template<class T> void coutVec(vector<T> tab){ for(T t : tab){ cout<<t<<" "; } cout<<"\n"; } //------------------------------------------ int n; int a[MAX]; int b[MAX]; bool check(int k) { if(k==1) return true; loop(i,0,n) b[i]=0; int f=a[0]; b[0]=a[0]; loop(i,1,n) { // ps(a[i]);ps(f); if(i-k>=0) f-=b[i-k]; if(a[i]<f) return false; b[i]=a[i]-f; // ps(b[i]); f+=b[i]; // pln(f); } return f==b[n-k]; } int findK() { int s=1; int e=n; while(s<e) { int m=(s+e+1)/2; if(check(m)) { s=m; } else { e=m-1; } } return s; } int main(){ ios_base::sync_with_stdio(0); cin>>n; ll S=0; loop(i,0,n) { cin>>a[i]; S += (ll) a[i]; } int maxi=1; // pln(S); loop(i,2,n+1) { if(S%i==0 && check(i)) maxi = max(maxi,i); } pln(maxi); } |
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