#include <iostream>
using namespace std;
using ll = long long;
constexpr ll mod = 1'000'000'007;
constexpr ll szpotmod(ll a, ll b) {
if (b == 0) return 1;
ll p = szpotmod(a, b / 2);
p = (p * p) % mod;
if (b % 2 == 1) p = (p * a) % mod;
return p;
}
constexpr ll odw(ll a) {
return szpotmod(a, mod - 2);
}
constexpr ll max_index = 500500;
constexpr ll inf = max_index - 2;
ll a[max_index];
ll b[max_index];
ll next_poi[max_index];
ll sum_pref[max_index];
ll il_pref[max_index];
ll potential[max_index];
ll potential_suf[max_index];
int main() {
std::ios_base::sync_with_stdio(0);
cin.tie(0);
ll n, q;
cin >> n >> q;
for(int i = 1; i <= n; i++) {
cin >> a[i] >> b[i];
}
next_poi[n + 1] = inf;
ll il = 1;
for(int i = n; i >= 1; i--) {
if (b[i] > 1) {
next_poi[i] = i;
potential[i] = 0;
il = (il * b[i]) % mod;
}
else {
next_poi[i] = next_poi[i + 1];
potential[i] = (a[i] * il) % mod;
}
potential_suf[i] = (potential_suf[i + 1] + potential[i]) % mod;
}
next_poi[0] = next_poi[1];
il_pref[0] = 1;
for(int i = 1; i <= n; i++) {
sum_pref[i] = sum_pref[i - 1] + a[i];
il_pref[i] = (il_pref[i - 1] * b[i]) % mod;
}
ll x, l, r;
for(int i = 0; i < q; i++) {
cin >> x >> l >> r;
ll cur = l;
bool happy = false;
while(cur < r) {
ll skip_to = min(next_poi[cur + 1] - 1, r);
if (skip_to > cur + 1) {
ll add = sum_pref[skip_to] - sum_pref[cur];
if (x + add >= mod) happy = true;
x = (x + add) % mod;
cur = skip_to;
if (cur == r) break;
if (happy) break;
}
x = max(x + a[cur + 1], x * b[cur + 1]);
if (x >= mod) happy = true;
x = x % mod;
cur = cur + 1;
if (happy) break;
}
if (cur < r) {
ll mult = (il_pref[r] * odw(il_pref[cur])) % mod;
x = (x * mult) % mod;
ll add = (((potential_suf[cur + 1] - potential_suf[r + 1] + mod) % mod) * odw((il_pref[n] * odw(il_pref[r])) % mod)) % mod;
x = (x + add) % mod;
}
cout << x << "\n";
}
}
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 | #include <iostream> using namespace std; using ll = long long; constexpr ll mod = 1'000'000'007; constexpr ll szpotmod(ll a, ll b) { if (b == 0) return 1; ll p = szpotmod(a, b / 2); p = (p * p) % mod; if (b % 2 == 1) p = (p * a) % mod; return p; } constexpr ll odw(ll a) { return szpotmod(a, mod - 2); } constexpr ll max_index = 500500; constexpr ll inf = max_index - 2; ll a[max_index]; ll b[max_index]; ll next_poi[max_index]; ll sum_pref[max_index]; ll il_pref[max_index]; ll potential[max_index]; ll potential_suf[max_index]; int main() { std::ios_base::sync_with_stdio(0); cin.tie(0); ll n, q; cin >> n >> q; for(int i = 1; i <= n; i++) { cin >> a[i] >> b[i]; } next_poi[n + 1] = inf; ll il = 1; for(int i = n; i >= 1; i--) { if (b[i] > 1) { next_poi[i] = i; potential[i] = 0; il = (il * b[i]) % mod; } else { next_poi[i] = next_poi[i + 1]; potential[i] = (a[i] * il) % mod; } potential_suf[i] = (potential_suf[i + 1] + potential[i]) % mod; } next_poi[0] = next_poi[1]; il_pref[0] = 1; for(int i = 1; i <= n; i++) { sum_pref[i] = sum_pref[i - 1] + a[i]; il_pref[i] = (il_pref[i - 1] * b[i]) % mod; } ll x, l, r; for(int i = 0; i < q; i++) { cin >> x >> l >> r; ll cur = l; bool happy = false; while(cur < r) { ll skip_to = min(next_poi[cur + 1] - 1, r); if (skip_to > cur + 1) { ll add = sum_pref[skip_to] - sum_pref[cur]; if (x + add >= mod) happy = true; x = (x + add) % mod; cur = skip_to; if (cur == r) break; if (happy) break; } x = max(x + a[cur + 1], x * b[cur + 1]); if (x >= mod) happy = true; x = x % mod; cur = cur + 1; if (happy) break; } if (cur < r) { ll mult = (il_pref[r] * odw(il_pref[cur])) % mod; x = (x * mult) % mod; ll add = (((potential_suf[cur + 1] - potential_suf[r + 1] + mod) % mod) * odw((il_pref[n] * odw(il_pref[r])) % mod)) % mod; x = (x + add) % mod; } cout << x << "\n"; } } |
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