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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 |
---|---|---|---|---|---|---|---|---|---|
#168983 | #6417. Classical Summation Problem | fryan | WA | 87ms | 135144kb | C++20 | 3.0kb | 2023-09-09 09:54:32 | 2023-09-09 09:54:34 |
Judging History
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;
if (k%2) {cout<<(n+1)/2*binpow(n,k); 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;
}
cout<<(n+1)/2*binpow(n,k)-b/2;
return 0;
}
详细
Test #1:
score: 100
Accepted
time: 87ms
memory: 134864kb
input:
3 2
output:
14
result:
ok 1 number(s): "14"
Test #2:
score: 0
Accepted
time: 1ms
memory: 3668kb
input:
5 3
output:
375
result:
ok 1 number(s): "375"
Test #3:
score: -100
Wrong Answer
time: 73ms
memory: 135144kb
input:
2 2
output:
3
result:
wrong answer 1st numbers differ - expected: '5', found: '3'