# | Time | Username | Problem | Language | Result | Execution time | Memory |
---|---|---|---|---|---|---|---|
22610 | 카시코이 (#40) | Unifying Values (KRIII5_UV) | C++98 | 0 ms | 0 KiB |
This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#include <cstdio>
#include <cstring>
#include <vector>
#include <unordered_map>
#include <algorithm>
using namespace std;
const int MOD = 1000000007;
int n;
long long arr[10004];
long long sum[10004];
long long allsum;
int d[2][10004];
int main() {
//freopen("input.txt", "r", stdin);
scanf("%d", &n);
for (int i = 1; i <= n; ++i) {
scanf("%lld", &arr[i]);
sum[i] = sum[i - 1] + arr[i];
}
allsum = sum[n];
unordered_map<long long, vector<int>> posbysum;
for (int i = 0; i <= n; ++i) {
posbysum[sum[i]];
posbysum[sum[i]].push_back(i);
}
vector<int> cand;
for (int i = 2; i <= n; ++i) {
if (allsum % i == 0) {
cand.push_back(i);
}
}
long long ans = 0;
if (allsum == 0) {
long long targetsum = 0;
vector<int> nxtp(n + 1);
for (int j = 0; j < n; ++j) {
long long sumi = sum[j] + targetsum;
vector<int>& posv = posbysum[sumi];
nxtp[j] = upper_bound(posv.begin(), posv.end(), j) - posv.begin();
}
d[0][0] = 1;
for (int k = 1; k <= n; ++k) {
memset(d[k % 2], 0, sizeof(d[k % 2]));
for (int j = 0; j < n; ++j) {
long long sumi = sum[j] + targetsum;
vector<int>& posv = posbysum[sumi];
auto it = posv.begin() + nxtp[j];
while (it != posv.end()) {
d[k % 2][*it] = (d[k % 2][*it] + d[1 - k % 2][j]) % MOD;
++it;
}
}
if (k >= 2) ans += d[k % 2][n];
}
printf("%d\n", ans % MOD);
return 0;
}
for (int cnt : cand) {
long long targetsum = allsum / cnt;
vector<vector<int>> idxs(n + 1);
vector<vector<int>> sum1(n + 1), prefix(n + 1);
idxs[0].push_back(0);
sum1[0].push_back(1);
prefix[0].push_back(1);
for (int k = 1; k <= cnt; ++k) {
long long ss = targetsum * k;
idxs[k] = posbysum[ss];
sum1[k].assign(idxs[k].size(), 0);
prefix[k].assign(idxs[k].size(), 0);
int p = 0;
for (int j = 0; j < idxs[k].size(); ++j) {
while (p < idxs[k - 1].size() && idxs[k - 1][p] < idxs[k][j]) {
++p;
}
sum1[k][j] = (p == 0) ? 0 : prefix[k - 1][p - 1];
prefix[k][j] = (j == 0 ? 0 : prefix[k][j - 1]) + sum1[k][j];
prefix[k][j] %= MOD;
}
}
ans += prefix[cnt].back();
}
printf("%d\n", ans % MOD);
return 0;
}