mirror of
https://git.sb/baoshuo/OI-codes.git
synced 2024-12-25 17:32:01 +00:00
86 lines
1.6 KiB
C++
86 lines
1.6 KiB
C++
#include <iostream>
|
|
#include <vector>
|
|
|
|
using std::cin;
|
|
using std::cout;
|
|
const char endl = '\n';
|
|
|
|
const int N = 1e5 + 5;
|
|
const int mod = 1e9 + 7;
|
|
|
|
int n, m, q, p[N], s[N], c[N], ans[N];
|
|
std::vector<int> g[N];
|
|
std::vector<std::pair<int, int>> qs[N];
|
|
|
|
int binpow(int a, int b) {
|
|
int res = 1;
|
|
a %= mod;
|
|
|
|
while (b) {
|
|
if (b & 1) res = static_cast<long long>(res) * a % mod;
|
|
a = static_cast<long long>(a) * a % mod;
|
|
b >>= 1;
|
|
}
|
|
|
|
return res;
|
|
}
|
|
|
|
inline int lowbit(int x) {
|
|
return x & -x;
|
|
}
|
|
|
|
void add(int x, int y) {
|
|
for (; x; x -= lowbit(x)) c[x] = (c[x] + y) % mod;
|
|
}
|
|
|
|
int sum(int x) {
|
|
int res = 0;
|
|
for (; x <= n; x += lowbit(x)) res = (res + c[x]) % mod;
|
|
return res;
|
|
}
|
|
|
|
int main() {
|
|
std::ios::sync_with_stdio(false);
|
|
cin.tie(nullptr);
|
|
|
|
cin >> n >> m >> q;
|
|
|
|
for (int i = 1, a, b; i <= n; i++) {
|
|
cin >> a >> b;
|
|
|
|
p[i] = static_cast<long long>(a) * binpow(b, mod - 2) % mod;
|
|
s[i] = (s[i - 1] + p[i]) % mod;
|
|
}
|
|
|
|
for (int i = 1, u, v; i <= m; i++) {
|
|
cin >> u >> v;
|
|
|
|
if (u > v) std::swap(u, v);
|
|
|
|
g[v].push_back(u);
|
|
}
|
|
|
|
for (int i = 1, l, r; i <= q; i++) {
|
|
cin >> l >> r;
|
|
|
|
ans[i] = (s[r] - s[l - 1]) % mod;
|
|
qs[r].emplace_back(i, l);
|
|
}
|
|
|
|
for (int i = 1; i <= n; i++) {
|
|
for (int v : g[i]) {
|
|
add(v, static_cast<long long>(p[i]) * p[v] % mod);
|
|
}
|
|
|
|
for (auto t : qs[i]) {
|
|
ans[t.first] = (ans[t.first] - sum(t.second)) % mod;
|
|
}
|
|
}
|
|
|
|
for (int i = 1; i <= q; i++) {
|
|
cout << (static_cast<long long>(ans[i]) % mod + mod) % mod << endl;
|
|
}
|
|
|
|
return 0;
|
|
}
|