#include <bits/stdc++.h> using namespace std; constexpr int mod = 1e9+7, B = 300, maxn = 1e5+10; int add[B][B], dp[maxn]; vector<pair<int,int>> upd[maxn]; // add when adding the dp to remove it later, just save the value to remove and the periodicity inline void add_self(int& a, int b) { a += b; a %= mod; } int main() { int n; scanf("%d", &n); dp[0] = 1; int ans = 0; for(int i = 0; i < n; i++) { int d, x; scanf("%d %d", &d, &x); for(auto [period, value] : upd[i]) add_self(add[period][i % period], mod - value); for(int k = 1; k < B; k++) add_self(dp[i], add[k][i % k]); add_self(ans, dp[i]); if(!d) continue; if(d >= B) for(int j = 1; j <= x && i + j * d < maxn; j++) // shouldn't need the 1ll* here add_self(dp[i + j * d], dp[i]); else { add_self(add[d][i % d], dp[i]); if(i + 1ll * (x + 1) * d < maxn) upd[i + (x + 1) * d].push_back({d, dp[i]}); } } printf("%d\n", ans); }

Main.cpp: In function 'int main()':
Main.cpp:13:17: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   13 |     int n; scanf("%d", &n);
      |            ~~~~~^~~~~~~~~~
Main.cpp:17:24: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   17 |         int d, x; scanf("%d %d", &d, &x);
      |                   ~~~~~^~~~~~~~~~~~~~~~~