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IDProblemSubmitterResultTimeMemoryLanguageFile sizeSubmit timeJudge time
#169004#6417. Classical Summation ProblemfryanAC ✓212ms136432kbC++203.1kb2023-09-09 10:36:062023-09-09 10:36:08

Judging History

你现在查看的是最新测评结果

  • [2023-09-09 10:36:08]
  • 评测
  • 测评结果:AC
  • 用时:212ms
  • 内存:136432kb
  • [2023-09-09 10:36:06]
  • 提交

answer

// Problem: A - W1P1: XOR Clique
// Contest: Virtual Judge - 602 - Season 2023 - HW Series 2
// URL: https://vjudge.net/contest/580028#problem/A
// Memory Limit: 253 MB
// Time Limit: 1000 ms
// 
// Powered by CP Editor (https://cpeditor.org)


#include <algorithm>
#include <array>
#include <bitset>
#include <cassert>
#include <cctype>
#include <cfenv>
#include <cfloat>
#include <chrono>
#include <cinttypes>
#include <climits>
#include <cmath>
#include <complex>
#include <cstdarg>
#include <cstddef>
#include <cstdint>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <deque>
#include <fstream>
#include <functional>
#include <immintrin.h>
#include <initializer_list>
#include <iomanip>
#include <ios>
#include <iostream>
#include <istream>
#include <iterator>
#include <limits>
#include <list>
#include <map>
#include <memory>
#include <new>
#include <numeric>
#include <ostream>
#include <queue>
#include <random>
#include <set>
#include <sstream>
#include <stack>
#include <streambuf>
#include <string>
#include <tuple>
#include <type_traits>
#include <variant>
using namespace std;

//numbers
using ll=long long;
#define int ll
using ld=long double;
//pairs
#define P pair
#define pi P<int,int>
#define ff first
#define ss second
#define mp make_pair
//std data structure
#define all(x) begin(x), end(x)
#define sz(x) (int) (x).size()
//vectors
#define V vector
#define vi V<int>
#define v2i V<vi>
#define v3i V<v2i>
#define vpi V<pi>
#define vsi V<si>
#define pb push_back
//sets
#define S set
#define MS multiset
#define US unordered_set
#define si S<int>
#define msi MS<int>
#define usi US<int>
#define ins insert
#define era erase
//maps
#define M map
#define UM unordered_map
#define mii M<int,int>
#define mivi UM<int,vi>
#define misi UM<int,si>
#define umii UM<int,int>
#define umivi UM<int,vi>
#define umisi UM<int,si>
//queues
#define Q queue
#define PQ priority_queue
#define qi Q<int>
#define qpi Q<pi>
#define pqi PQ<int>
#define rpqi PQ<int,vi,greater<int> >
#define pqpi PQ<pi>
#define rpqpi PQ<pi,vpi,greater<pi> >
//constants
const int MOD=998244353;
const int INF=922337203685477580;
//nt functions
int binpow(int a, int b, int m=MOD) {
    a%=m; int res=1;
    while (b>0) {
        if (b&1) res=res*a%m;
        a=a*a%m;
        b>>=1;
    }
    return res;
}
int gcd (int a, int b) {
    return b?gcd (b,a%b):a;
}
int lcm (int a, int b) {
    return a/gcd(a,b)*b;
}
int inv(int i, int m=MOD) {
	return binpow(i, m-2, m);
}
vi f;
void fs() {
	f.pb(1);
	for (int i=1; i<1e7; i++) {
		f.pb(i*f[i-1]); f[i]%=MOD;
	}
}
int comb(int n, int k) {
	return ((f[n]*inv(f[n-k]))%MOD*inv(f[k]))%MOD;
}
//new header wip

signed main() {
	ios::sync_with_stdio(false); cin.tie(nullptr);
	int n,k; cin>>n>>k;
	
	int n2=((n+1)*inv(2))%MOD;
	if (k%2) {
		cout<<(n2*binpow(n,k))%MOD;
		return 0;
	}
	int b=0; fs();
	for (int i=0; i<n; i++) {
		b+=((comb(k,k/2)*binpow(i,k/2))%MOD*binpow(n-i,k/2))%MOD;
		b%=MOD;
	}
	int ans=n2*binpow(n,k)-b*inv(2); ans%=MOD; ans+=MOD; ans%=MOD;
	cout<<ans;

	return 0;
}

Details

Tip: Click on the bar to expand more detailed information

Test #1:

score: 100
Accepted
time: 74ms
memory: 135236kb

input:

3 2

output:

14

result:

ok 1 number(s): "14"

Test #2:

score: 0
Accepted
time: 1ms
memory: 3648kb

input:

5 3

output:

375

result:

ok 1 number(s): "375"

Test #3:

score: 0
Accepted
time: 82ms
memory: 134840kb

input:

2 2

output:

5

result:

ok 1 number(s): "5"

Test #4:

score: 0
Accepted
time: 1ms
memory: 3656kb

input:

10 9

output:

508778235

result:

ok 1 number(s): "508778235"

Test #5:

score: 0
Accepted
time: 1ms
memory: 3584kb

input:

69 3

output:

11497815

result:

ok 1 number(s): "11497815"

Test #6:

score: 0
Accepted
time: 1ms
memory: 3644kb

input:

994 515

output:

33689623

result:

ok 1 number(s): "33689623"

Test #7:

score: 0
Accepted
time: 87ms
memory: 135968kb

input:

4476 6182

output:

114894183

result:

ok 1 number(s): "114894183"

Test #8:

score: 0
Accepted
time: 1ms
memory: 3584kb

input:

58957 12755

output:

932388891

result:

ok 1 number(s): "932388891"

Test #9:

score: 0
Accepted
time: 95ms
memory: 135804kb

input:

218138 28238

output:

392861201

result:

ok 1 number(s): "392861201"

Test #10:

score: 0
Accepted
time: 157ms
memory: 134560kb

input:

644125 316810

output:

420621854

result:

ok 1 number(s): "420621854"

Test #11:

score: 0
Accepted
time: 153ms
memory: 134428kb

input:

612914 505428

output:

973686286

result:

ok 1 number(s): "973686286"

Test #12:

score: 0
Accepted
time: 1ms
memory: 3656kb

input:

998216 938963

output:

251335926

result:

ok 1 number(s): "251335926"

Test #13:

score: 0
Accepted
time: 1ms
memory: 3580kb

input:

990516 996933

output:

549551960

result:

ok 1 number(s): "549551960"

Test #14:

score: 0
Accepted
time: 205ms
memory: 134564kb

input:

999019 999012

output:

637189128

result:

ok 1 number(s): "637189128"

Test #15:

score: 0
Accepted
time: 202ms
memory: 135496kb

input:

999928 999950

output:

185229465

result:

ok 1 number(s): "185229465"

Test #16:

score: 0
Accepted
time: 1ms
memory: 3580kb

input:

999999 999999

output:

384164916

result:

ok 1 number(s): "384164916"

Test #17:

score: 0
Accepted
time: 198ms
memory: 135568kb

input:

999999 1000000

output:

696165930

result:

ok 1 number(s): "696165930"

Test #18:

score: 0
Accepted
time: 0ms
memory: 3656kb

input:

1000000 999999

output:

219071706

result:

ok 1 number(s): "219071706"

Test #19:

score: 0
Accepted
time: 194ms
memory: 136080kb

input:

1000000 1000000

output:

128206597

result:

ok 1 number(s): "128206597"

Test #20:

score: 0
Accepted
time: 79ms
memory: 135820kb

input:

2 10

output:

1410

result:

ok 1 number(s): "1410"

Test #21:

score: 0
Accepted
time: 95ms
memory: 135824kb

input:

84 16

output:

297627153

result:

ok 1 number(s): "297627153"

Test #22:

score: 0
Accepted
time: 82ms
memory: 135600kb

input:

643 800

output:

489237163

result:

ok 1 number(s): "489237163"

Test #23:

score: 0
Accepted
time: 71ms
memory: 134880kb

input:

9903 880

output:

595167333

result:

ok 1 number(s): "595167333"

Test #24:

score: 0
Accepted
time: 104ms
memory: 136180kb

input:

97446 89750

output:

410205549

result:

ok 1 number(s): "410205549"

Test #25:

score: 0
Accepted
time: 100ms
memory: 136364kb

input:

186460 646474

output:

32638530

result:

ok 1 number(s): "32638530"

Test #26:

score: 0
Accepted
time: 126ms
memory: 135840kb

input:

508940 244684

output:

598321755

result:

ok 1 number(s): "598321755"

Test #27:

score: 0
Accepted
time: 122ms
memory: 136052kb

input:

583646 557758

output:

858695621

result:

ok 1 number(s): "858695621"

Test #28:

score: 0
Accepted
time: 185ms
memory: 135688kb

input:

969610 992608

output:

256683498

result:

ok 1 number(s): "256683498"

Test #29:

score: 0
Accepted
time: 212ms
memory: 136432kb

input:

995106 996434

output:

411791999

result:

ok 1 number(s): "411791999"

Test #30:

score: 0
Accepted
time: 193ms
memory: 135140kb

input:

999961 999872

output:

61222370

result:

ok 1 number(s): "61222370"

Test #31:

score: 0
Accepted
time: 190ms
memory: 135732kb

input:

999977 999908

output:

831096762

result:

ok 1 number(s): "831096762"

Test #32:

score: 0
Accepted
time: 211ms
memory: 136188kb

input:

999992 999998

output:

562977678

result:

ok 1 number(s): "562977678"

Test #33:

score: 0
Accepted
time: 94ms
memory: 135376kb

input:

1000000 2

output:

118436113

result:

ok 1 number(s): "118436113"

Test #34:

score: 0
Accepted
time: 97ms
memory: 135660kb

input:

2 1000000

output:

298823641

result:

ok 1 number(s): "298823641"