QOJ.ac
QOJ
ID | Problem | Submitter | Result | Time | Memory | Language | File size | Submit time | Judge time |
---|---|---|---|---|---|---|---|---|---|
#190685 | #6736. Alice and Bob | koifish# | AC ✓ | 104ms | 159908kb | C++17 | 1.7kb | 2023-09-29 12:50:22 | 2023-09-29 12:50:22 |
Judging History
answer
#include <bits/stdc++.h>
#define ll long long
#define int ll
#define mp make_pair
#define fi first
#define se second
#define pb push_back
#define vi vector<int>
#define pi pair<int, int>
#define vpii vector<pi>
#define il inline
#define ri register
#define all(a) a.begin(), a.end()
#define fr(a) freopen(a, "r", stdin)
#define fo(a) freopen(a, "w", stdout);
#define mod 998244353
#define debug puts("------------------------")
#define lowbit(x) (x&-x)
#define ls(x) x << 1
#define rs(x) x << 1 | 1
template<typename T> bool chkmin(T &a, T b){return (b < a) ? a = b, 1 : 0;}
template<typename T> bool chkmax(T &a, T b){return (b > a) ? a = b, 1 : 0;}
ll ksm(ll a, ll b) {if (b == 0) return 1; ll ns = ksm(a, b >> 1); ns = ns * ns % mod; if (b & 1) ns = ns * a % mod; return ns;}
void Read(int &a) {a=0;int c=getchar(),b=1; while(c>'9'||c<'0') {if(c=='-')b=-1;c=getchar();} while(c>='0'&&c<='9') a=(a<<3)+(a<<1)+c-48,c=getchar();a*=b; }
int read() {int a=0,c=getchar(),b=1; while(c>'9'||c<'0') {if(c=='-')b=-1;c=getchar();} while(c>='0'&&c<='9') a=(a<<3)+(a<<1)+c-48,c=getchar();return a*=b; }
void write(int x) {if(x>9)write(x/10);putchar('0'+x%10);}
void W(int x) {if(x<0){putchar('-'),x=-x;}write(x);}
#define LOCAL
using namespace std;
const int maxn = 1e7 + 5;
/**/
int n, f[maxn], ans, ifac[maxn];
/**/
int A(int N, int M)
{
if(N < M) return 0;
return f[N] * ifac[N-M] % mod;
}
signed main()
{
f[0] = ifac[0] = 1;
n = read();
for(int i = 1; i <= n; i++) f[i] = f[i - 1] * i % mod;
ifac[n] = ksm(f[n], mod - 2);
for(int i = n - 1; i >= 1; i--) ifac[i] = ifac[i + 1] * (i + 1) % mod;
for(int i = 1; i <= n; i++)
{
ans += A(n-i, i-1) * A(n - i, n - i) % mod;
ans %= mod;
}
cout << ans;
return 0;
}
Details
Tip: Click on the bar to expand more detailed information
Test #1:
score: 100
Accepted
time: 1ms
memory: 5676kb
input:
1
output:
1
result:
ok 1 number(s): "1"
Test #2:
score: 0
Accepted
time: 1ms
memory: 5540kb
input:
2
output:
1
result:
ok 1 number(s): "1"
Test #3:
score: 0
Accepted
time: 1ms
memory: 5636kb
input:
10
output:
997920
result:
ok 1 number(s): "997920"
Test #4:
score: 0
Accepted
time: 0ms
memory: 5576kb
input:
100
output:
188898954
result:
ok 1 number(s): "188898954"
Test #5:
score: 0
Accepted
time: 0ms
memory: 5652kb
input:
4
output:
10
result:
ok 1 number(s): "10"
Test #6:
score: 0
Accepted
time: 1ms
memory: 5728kb
input:
8
output:
12336
result:
ok 1 number(s): "12336"
Test #7:
score: 0
Accepted
time: 0ms
memory: 5736kb
input:
16
output:
373118483
result:
ok 1 number(s): "373118483"
Test #8:
score: 0
Accepted
time: 1ms
memory: 5580kb
input:
32
output:
314585464
result:
ok 1 number(s): "314585464"
Test #9:
score: 0
Accepted
time: 0ms
memory: 5652kb
input:
64
output:
627827331
result:
ok 1 number(s): "627827331"
Test #10:
score: 0
Accepted
time: 1ms
memory: 5640kb
input:
128
output:
828497685
result:
ok 1 number(s): "828497685"
Test #11:
score: 0
Accepted
time: 0ms
memory: 5736kb
input:
256
output:
65697890
result:
ok 1 number(s): "65697890"
Test #12:
score: 0
Accepted
time: 0ms
memory: 5664kb
input:
512
output:
854187619
result:
ok 1 number(s): "854187619"
Test #13:
score: 0
Accepted
time: 1ms
memory: 5588kb
input:
1024
output:
513823539
result:
ok 1 number(s): "513823539"
Test #14:
score: 0
Accepted
time: 20ms
memory: 27776kb
input:
1361956
output:
617368199
result:
ok 1 number(s): "617368199"
Test #15:
score: 0
Accepted
time: 75ms
memory: 125596kb
input:
7579013
output:
827172636
result:
ok 1 number(s): "827172636"
Test #16:
score: 0
Accepted
time: 92ms
memory: 133472kb
input:
8145517
output:
710624331
result:
ok 1 number(s): "710624331"
Test #17:
score: 0
Accepted
time: 72ms
memory: 101976kb
input:
6140463
output:
707600568
result:
ok 1 number(s): "707600568"
Test #18:
score: 0
Accepted
time: 37ms
memory: 60028kb
input:
3515281
output:
698302413
result:
ok 1 number(s): "698302413"
Test #19:
score: 0
Accepted
time: 62ms
memory: 116952kb
input:
6969586
output:
69470392
result:
ok 1 number(s): "69470392"
Test #20:
score: 0
Accepted
time: 37ms
memory: 51932kb
input:
2888636
output:
433579983
result:
ok 1 number(s): "433579983"
Test #21:
score: 0
Accepted
time: 88ms
memory: 159908kb
input:
9999998
output:
758172780
result:
ok 1 number(s): "758172780"
Test #22:
score: 0
Accepted
time: 96ms
memory: 159844kb
input:
9999999
output:
605195495
result:
ok 1 number(s): "605195495"
Test #23:
score: 0
Accepted
time: 104ms
memory: 159904kb
input:
10000000
output:
866813682
result:
ok 1 number(s): "866813682"