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QOJ
ID | 题目 | 提交者 | 结果 | 用时 | 内存 | 语言 | 文件大小 | 提交时间 | 测评时间 |
---|---|---|---|---|---|---|---|---|---|
#658977 | #8339. Rooted Tree | the_foo# | AC ✓ | 1259ms | 159392kb | C++20 | 2.5kb | 2024-10-19 18:05:40 | 2024-10-19 18:05:46 |
Judging History
answer
#include <bits/stdc++.h>
using namespace std;
using LL = long long;
constexpr int mod = 1E9 + 9;
struct mint {
LL x;
mint(int _x = 0) {
x = _x;
}
mint operator+(mint p) {
LL res = x + p.x;
while (res >= mod) res -= mod;
return res;
}
mint operator-(mint p) {
LL res = x - p.x;
while (res < 0) res += mod;
return res;
}
mint operator*(mint p) {
return x * p.x % mod;
}
mint pow(LL b) {
mint res = 1, a = *this;
while (b) {
if (b & 1) res = res * a;
a = a * a;
b >>= 1;
}
return res;
}
mint operator/(mint p) {
return (*this) * p.pow(mod - 2);
}
};
// void solve() {
// int m, k;
// cin >> m >> k;
//
// vector<mint> pre(k + 1);
// pre[0] = 1;
// for (int i = 1; i <= k; i++) {
// mint sum = mint(i) * (m - 1) + 1;
// pre[i] = pre[i - 1] * (sum - 1) / sum;
// }
//
// vector<mint> suf(k + 1);
// suf[k] = 1;
// for (int i = k - 1; i >= 1; i--) {
// mint sum = mint(i) * (m - 1) + 1;
// suf[i] = suf[i + 1] * (sum - 1) / sum;
// }
//
// vector<mint> p(k + 1);
// mint pp = 1;
// p[0] = p[1] = 0;
// for (int i = 2; i <= k; i++) {
// p[i] = p[i - 1];
// p[i] = (mint(1) - p[i - 1]) * suf[i - 1] + p[i];
// }
//
// for (int i = 1; i <= k; i++) {
// cout << p[i].x << " \n"[i == k];
// }
//
// mint sum = 1, ans = 0;
// for (int i = 1; i <= k; i++) {
// sum = sum * m;
// ans = ans + sum * i * (mint(1) - p[i]);
// }
//
// cout << ans.x << "\n";
// }
void solve() {
int m, k;
cin >> m >> k;
vector<mint> dep(k + 1);
dep[0] = 0;
mint ans = 0;
vector<mint> sum(k + 1);
sum[0] = 1;
for (int i = 1; i <= k; i++) {
sum[i] = sum[i - 1] + m - 1;
}
for (int i = 1; i <= k; i++) {
//mint t = dep[i - 1] / sum[i - 1];
dep[i] = //(t + 1) * m - dep[i - 1];
(dep[i-1]*sum[i-1]+(dep[i-1]+1)*m-dep[i-1])/sum[i];
ans = ans + (dep[i-1]+1)*m;
}
cout << ans.x << "\n";
}
int main() {
ios::sync_with_stdio(0);
cin.tie(0);
int t = 1;
// cin >> t;
while (t--) {
solve();
}
}
/*
*2 3
333333337
500000005 666666673 750000007
0 750000007 375000004
17
*/
详细
Test #1:
score: 100
Accepted
time: 0ms
memory: 3800kb
input:
6 2
output:
18
result:
ok 1 number(s): "18"
Test #2:
score: 0
Accepted
time: 0ms
memory: 3748kb
input:
2 6
output:
600000038
result:
ok 1 number(s): "600000038"
Test #3:
score: 0
Accepted
time: 75ms
memory: 12628kb
input:
83 613210
output:
424200026
result:
ok 1 number(s): "424200026"
Test #4:
score: 0
Accepted
time: 841ms
memory: 107952kb
input:
48 6713156
output:
198541581
result:
ok 1 number(s): "198541581"
Test #5:
score: 0
Accepted
time: 0ms
memory: 3796kb
input:
1 111
output:
6216
result:
ok 1 number(s): "6216"
Test #6:
score: 0
Accepted
time: 921ms
memory: 117328kb
input:
28 7304152
output:
457266679
result:
ok 1 number(s): "457266679"
Test #7:
score: 0
Accepted
time: 511ms
memory: 67092kb
input:
38 4101162
output:
232117382
result:
ok 1 number(s): "232117382"
Test #8:
score: 0
Accepted
time: 1245ms
memory: 158444kb
input:
51 9921154
output:
340670552
result:
ok 1 number(s): "340670552"
Test #9:
score: 0
Accepted
time: 224ms
memory: 31352kb
input:
79 1801157
output:
620550406
result:
ok 1 number(s): "620550406"
Test #10:
score: 0
Accepted
time: 683ms
memory: 87824kb
input:
22 5417157
output:
457449071
result:
ok 1 number(s): "457449071"
Test #11:
score: 0
Accepted
time: 401ms
memory: 53292kb
input:
25 3210162
output:
36368303
result:
ok 1 number(s): "36368303"
Test #12:
score: 0
Accepted
time: 363ms
memory: 48752kb
input:
67 2919160
output:
935195555
result:
ok 1 number(s): "935195555"
Test #13:
score: 0
Accepted
time: 1084ms
memory: 137632kb
input:
77 8613163
output:
482832472
result:
ok 1 number(s): "482832472"
Test #14:
score: 0
Accepted
time: 1254ms
memory: 159300kb
input:
90 10000000
output:
275581651
result:
ok 1 number(s): "275581651"
Test #15:
score: 0
Accepted
time: 1259ms
memory: 159392kb
input:
99 9999999
output:
126087169
result:
ok 1 number(s): "126087169"
Test #16:
score: 0
Accepted
time: 1255ms
memory: 159384kb
input:
100 10000000
output:
451590067
result:
ok 1 number(s): "451590067"
Extra Test:
score: 0
Extra Test Passed