[Codeforces Round #601 (Div. 2)]E2. Send Boxes to Alice(Hard Version)

简化版https://blog.csdn.net/qq_33831360/article/details/103170669
就是数据变大了

优化：k不是sqrt枚举，因为因子nk（个一组）结果可能不比因子k（个一组）好，所以分解质因数枚举质因子k

枚举的方法：移动到点i后，积累了had 计算过程模拟的是后移，但实际上，对于这k个礼物，前一部分后移，随着had变大，后一部分前移。是有一致性的，且后部分模拟后移只是为了计算需要前移多少。

#include 
#include 
#include 
#include 
 
using namespace std;
#define int long long 
int n;
typedef long long LL;
LL a[1000003];
 
LL calc(int x) {
	LL ans = 0;
	LL had = 0;
    for (int i = 1; i <= n; i++) {
    	had = had+a[i];
		if (had > x) had %= x;
    	ans += min(had,x-had);
	}
	return ans;
}
 
main() {
	LL sum = 0;
	cin >> n;
	for (int i = 1; i <= n; i++) {
		scanf("%I64d",&a[i]);
		sum += a[i];
	}
	if (sum <= 1) {
		puts("-1");
		return 0;
	} 
	LL ans = (LL)1e18;
	for (LL i = 2; i <= sqrt(sum); i++)
		if (sum % i == 0) {
			ans = min(ans,calc(i));
			while (sum%i == 0) sum /= i;
		}
	if (sum > 1) ans = min(ans,calc(sum));
    cout << ans;
	return 0;
}