1 条题解
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0
#include <bits/stdc++.h> #define int long long #define mod 998244353 using namespace std; int n, f[1000005]; unordered_map<int, int> mp; void init() { f[1] = 1; for (int i = 1; i <= 1000000; i++) for (int j = i + i; j <= 1000000; j += i) f[j] = (f[j] + f[i]) % mod; for (int i = 1; i <= 1000000; i++) f[i] = (f[i] + f[i - 1]) % mod; } int solve(int x) { if (x <= 1000000) return f[x]; if (mp.count(x)) return mp[x]; else { int ans = 1; for (int l = 2, r; l <= x; l = r + 1) { r = x / (x / l); ans = (ans + (r - l + 1) * solve(x / l)) % mod; } return mp[x] = ans; } } signed main() { init(); cin >> n; cout << solve(n); return 0; }
- 1
信息
- ID
- 9761
- 时间
- 2000ms
- 内存
- 256MiB
- 难度
- 10
- 标签
- 递交数
- 1
- 已通过
- 1
- 上传者