QOJ.ac
QOJ
ID | Problem | Submitter | Result | Time | Memory | Language | File size | Submit time | Judge time |
---|---|---|---|---|---|---|---|---|---|
#472690 | #6417. Classical Summation Problem | UESTC_Snow_Halation | AC ✓ | 133ms | 19340kb | C++14 | 1.1kb | 2024-07-11 18:29:33 | 2024-07-11 18:29:33 |
Judging History
answer
#include <iostream>
#include <algorithm>
using namespace std;
typedef long long ll;
typedef double db;
const int N = 1e6 + 7;
const int Mod = 998244353;
ll qpow(ll x, ll y)
{
ll ret = 1;
while (y)
{
if (y & 1)
ret = ret * x % Mod;
x = x * x % Mod, y >>= 1;
}
return ret;
}
ll fac[N], ifac[N];
ll C(int n, int m)
{
return fac[n] * ifac[m] % Mod * ifac[n - m] % Mod;
}
int main()
{
// ios::sync_with_stdio(false);
int n, K;
cin >> n >> K;
fac[0] = 1;
for (int i = 1; i < N; i++)
fac[i] = fac[i - 1] * i % Mod;
ifac[N - 1] = qpow(fac[N - 1], Mod - 2);
for (int i = N - 2; ~i; i--)
ifac[i] = ifac[i + 1] * (i + 1) % Mod;
ll ans = (n + 1) * qpow(n, K) % Mod, tmp = 0;
if (K & 1)
;
else
{
for (int i = 1; i <= n; i++)
tmp = (tmp + qpow(i, K / 2) * qpow(n - i, K / 2) % Mod) % Mod;
ans = (ans - C(K, K / 2) * tmp % Mod + Mod) % Mod;
}
cout << ans * qpow(2ll, Mod - 2) % Mod;
}
Details
Tip: Click on the bar to expand more detailed information
Test #1:
score: 100
Accepted
time: 8ms
memory: 19256kb
input:
3 2
output:
14
result:
ok 1 number(s): "14"
Test #2:
score: 0
Accepted
time: 12ms
memory: 19272kb
input:
5 3
output:
375
result:
ok 1 number(s): "375"
Test #3:
score: 0
Accepted
time: 8ms
memory: 19324kb
input:
2 2
output:
5
result:
ok 1 number(s): "5"
Test #4:
score: 0
Accepted
time: 11ms
memory: 19332kb
input:
10 9
output:
508778235
result:
ok 1 number(s): "508778235"
Test #5:
score: 0
Accepted
time: 3ms
memory: 19252kb
input:
69 3
output:
11497815
result:
ok 1 number(s): "11497815"
Test #6:
score: 0
Accepted
time: 7ms
memory: 19268kb
input:
994 515
output:
33689623
result:
ok 1 number(s): "33689623"
Test #7:
score: 0
Accepted
time: 12ms
memory: 19252kb
input:
4476 6182
output:
114894183
result:
ok 1 number(s): "114894183"
Test #8:
score: 0
Accepted
time: 12ms
memory: 19312kb
input:
58957 12755
output:
932388891
result:
ok 1 number(s): "932388891"
Test #9:
score: 0
Accepted
time: 30ms
memory: 19256kb
input:
218138 28238
output:
392861201
result:
ok 1 number(s): "392861201"
Test #10:
score: 0
Accepted
time: 80ms
memory: 19260kb
input:
644125 316810
output:
420621854
result:
ok 1 number(s): "420621854"
Test #11:
score: 0
Accepted
time: 74ms
memory: 19256kb
input:
612914 505428
output:
973686286
result:
ok 1 number(s): "973686286"
Test #12:
score: 0
Accepted
time: 7ms
memory: 19252kb
input:
998216 938963
output:
251335926
result:
ok 1 number(s): "251335926"
Test #13:
score: 0
Accepted
time: 7ms
memory: 19312kb
input:
990516 996933
output:
549551960
result:
ok 1 number(s): "549551960"
Test #14:
score: 0
Accepted
time: 129ms
memory: 19260kb
input:
999019 999012
output:
637189128
result:
ok 1 number(s): "637189128"
Test #15:
score: 0
Accepted
time: 133ms
memory: 19136kb
input:
999928 999950
output:
185229465
result:
ok 1 number(s): "185229465"
Test #16:
score: 0
Accepted
time: 3ms
memory: 19340kb
input:
999999 999999
output:
384164916
result:
ok 1 number(s): "384164916"
Test #17:
score: 0
Accepted
time: 127ms
memory: 19332kb
input:
999999 1000000
output:
696165930
result:
ok 1 number(s): "696165930"
Test #18:
score: 0
Accepted
time: 7ms
memory: 19132kb
input:
1000000 999999
output:
219071706
result:
ok 1 number(s): "219071706"
Test #19:
score: 0
Accepted
time: 124ms
memory: 19256kb
input:
1000000 1000000
output:
128206597
result:
ok 1 number(s): "128206597"
Test #20:
score: 0
Accepted
time: 8ms
memory: 19260kb
input:
2 10
output:
1410
result:
ok 1 number(s): "1410"
Test #21:
score: 0
Accepted
time: 7ms
memory: 19192kb
input:
84 16
output:
297627153
result:
ok 1 number(s): "297627153"
Test #22:
score: 0
Accepted
time: 7ms
memory: 19308kb
input:
643 800
output:
489237163
result:
ok 1 number(s): "489237163"
Test #23:
score: 0
Accepted
time: 6ms
memory: 19132kb
input:
9903 880
output:
595167333
result:
ok 1 number(s): "595167333"
Test #24:
score: 0
Accepted
time: 21ms
memory: 19252kb
input:
97446 89750
output:
410205549
result:
ok 1 number(s): "410205549"
Test #25:
score: 0
Accepted
time: 33ms
memory: 19192kb
input:
186460 646474
output:
32638530
result:
ok 1 number(s): "32638530"
Test #26:
score: 0
Accepted
time: 66ms
memory: 19308kb
input:
508940 244684
output:
598321755
result:
ok 1 number(s): "598321755"
Test #27:
score: 0
Accepted
time: 73ms
memory: 19316kb
input:
583646 557758
output:
858695621
result:
ok 1 number(s): "858695621"
Test #28:
score: 0
Accepted
time: 121ms
memory: 19256kb
input:
969610 992608
output:
256683498
result:
ok 1 number(s): "256683498"
Test #29:
score: 0
Accepted
time: 132ms
memory: 19256kb
input:
995106 996434
output:
411791999
result:
ok 1 number(s): "411791999"
Test #30:
score: 0
Accepted
time: 115ms
memory: 19260kb
input:
999961 999872
output:
61222370
result:
ok 1 number(s): "61222370"
Test #31:
score: 0
Accepted
time: 131ms
memory: 19276kb
input:
999977 999908
output:
831096762
result:
ok 1 number(s): "831096762"
Test #32:
score: 0
Accepted
time: 132ms
memory: 19260kb
input:
999992 999998
output:
562977678
result:
ok 1 number(s): "562977678"
Test #33:
score: 0
Accepted
time: 13ms
memory: 19260kb
input:
1000000 2
output:
118436113
result:
ok 1 number(s): "118436113"
Test #34:
score: 0
Accepted
time: 7ms
memory: 19328kb
input:
2 1000000
output:
298823641
result:
ok 1 number(s): "298823641"