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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 |
---|---|---|---|---|---|---|---|---|---|
#204400 | #6736. Alice and Bob | kiwiHM# | AC ✓ | 108ms | 82052kb | C++14 | 861b | 2023-10-07 11:06:41 | 2023-10-07 11:06:43 |
Judging History
answer
#include <bits/stdc++.h>
using namespace std;
const int maxn = 1e7 + 5;
const int INF = 998244353;
int n;
int fac[maxn], ifac[maxn];
inline int qpow(int x, int y){
int ret = 1;
for(; y; y >>= 1){
if(y & 1) ret = 1ll * ret * x % INF;
x = 1ll * x * x % INF;
}
return ret;
}
inline int binom(int x, int y){
if(x > y) return 0;
return 1ll * fac[x] * ifac[y] % INF * ifac[x - y] % INF;
}
int main(){
scanf("%d", &n);
fac[0] = 1; for(int i = 1; i <= n; ++i) fac[i] = 1ll * fac[i - 1] * i % INF;
ifac[n] = qpow(fac[n], INF - 2); for(int i = n - 1; i >= 0; --i) ifac[i] = 1ll * ifac[i + 1] * (i + 1) % INF;
int ans = 0;
for(int i = 1; i <= n; ++i) if(n - i >= i - 1){
int res = 1ll * fac[n - i] * ifac[(n - i) - (i - 1)] % INF * fac[n - i] % INF;
ans = (ans + res) % INF;
}
printf("%d\n", ans);
return 0;
}
详细
Test #1:
score: 100
Accepted
time: 1ms
memory: 5916kb
input:
1
output:
1
result:
ok 1 number(s): "1"
Test #2:
score: 0
Accepted
time: 1ms
memory: 5920kb
input:
2
output:
1
result:
ok 1 number(s): "1"
Test #3:
score: 0
Accepted
time: 1ms
memory: 5848kb
input:
10
output:
997920
result:
ok 1 number(s): "997920"
Test #4:
score: 0
Accepted
time: 1ms
memory: 5904kb
input:
100
output:
188898954
result:
ok 1 number(s): "188898954"
Test #5:
score: 0
Accepted
time: 1ms
memory: 5984kb
input:
4
output:
10
result:
ok 1 number(s): "10"
Test #6:
score: 0
Accepted
time: 1ms
memory: 5972kb
input:
8
output:
12336
result:
ok 1 number(s): "12336"
Test #7:
score: 0
Accepted
time: 0ms
memory: 5900kb
input:
16
output:
373118483
result:
ok 1 number(s): "373118483"
Test #8:
score: 0
Accepted
time: 0ms
memory: 5968kb
input:
32
output:
314585464
result:
ok 1 number(s): "314585464"
Test #9:
score: 0
Accepted
time: 0ms
memory: 5920kb
input:
64
output:
627827331
result:
ok 1 number(s): "627827331"
Test #10:
score: 0
Accepted
time: 1ms
memory: 5840kb
input:
128
output:
828497685
result:
ok 1 number(s): "828497685"
Test #11:
score: 0
Accepted
time: 0ms
memory: 5844kb
input:
256
output:
65697890
result:
ok 1 number(s): "65697890"
Test #12:
score: 0
Accepted
time: 1ms
memory: 5816kb
input:
512
output:
854187619
result:
ok 1 number(s): "854187619"
Test #13:
score: 0
Accepted
time: 0ms
memory: 5888kb
input:
1024
output:
513823539
result:
ok 1 number(s): "513823539"
Test #14:
score: 0
Accepted
time: 17ms
memory: 19192kb
input:
1361956
output:
617368199
result:
ok 1 number(s): "617368199"
Test #15:
score: 0
Accepted
time: 69ms
memory: 64512kb
input:
7579013
output:
827172636
result:
ok 1 number(s): "827172636"
Test #16:
score: 0
Accepted
time: 94ms
memory: 68704kb
input:
8145517
output:
710624331
result:
ok 1 number(s): "710624331"
Test #17:
score: 0
Accepted
time: 67ms
memory: 52588kb
input:
6140463
output:
707600568
result:
ok 1 number(s): "707600568"
Test #18:
score: 0
Accepted
time: 30ms
memory: 34088kb
input:
3515281
output:
698302413
result:
ok 1 number(s): "698302413"
Test #19:
score: 0
Accepted
time: 72ms
memory: 60476kb
input:
6969586
output:
69470392
result:
ok 1 number(s): "69470392"
Test #20:
score: 0
Accepted
time: 31ms
memory: 31400kb
input:
2888636
output:
433579983
result:
ok 1 number(s): "433579983"
Test #21:
score: 0
Accepted
time: 96ms
memory: 82036kb
input:
9999998
output:
758172780
result:
ok 1 number(s): "758172780"
Test #22:
score: 0
Accepted
time: 108ms
memory: 82028kb
input:
9999999
output:
605195495
result:
ok 1 number(s): "605195495"
Test #23:
score: 0
Accepted
time: 104ms
memory: 82052kb
input:
10000000
output:
866813682
result:
ok 1 number(s): "866813682"