#include<bits/stdc++.h> using namespace std; #define int long long const int mod = 1e9+7; int n, d[100005], x[100005], S = 320, dp[100005], pfs[100005][325]; vector<int> adj[100005]; void solve() { cin >> n; for (int i = 1; i <= n; i++) { cin >> d[i] >> x[i]; if(d[i] > S) for (int j = i+d[i]; j <= min(n, i+d[i]*x[i]); j += d[i]) adj[j].push_back(i); } dp[1] = 1; int res = 0; for (int i = 1; i <= n; i++) { if(i!=1){ for (int j = 1; j <= S; j++) pfs[i][j] += pfs[max(0ll,i-j)][j], pfs[i][j] %= mod, pfs[i][j]=(pfs[i][j]+mod)%mod; for (int j = 1; j <= S; j++) dp[i] += pfs[i][j], dp[i]%=mod; for (int j: adj[i]) dp[i] += dp[j], dp[i] %= mod; } if(d[i] <= S) pfs[i][d[i]] += dp[i], pfs[min(n+2,i+d[i]*(x[i]+1))][d[i]] -= dp[i]; res += dp[i], res %= mod; } cout << res; } signed main() { ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0); if(fopen("input.inp","r")){ freopen("input.inp", "r", stdin); freopen("output.out", "w", stdout); } int t = 1; // cin >> t; while(t--) { solve(); } }

Main.cpp: In function 'int main()':
Main.cpp:31:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   31 |   freopen("input.inp", "r", stdin);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:32:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   32 |   freopen("output.out", "w", stdout);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~