NOI.AC
| 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 |
|---|---|---|---|---|---|---|---|---|---|
| #185072 | #2662. 折跃 | snow_trace | 100 | 3146ms | 391792kb | C++11 | 633b | 2023-09-21 09:32:47 | 2023-09-21 12:23:20 |
answer
#include<bits/stdc++.h>
using namespace std;
#define int long long
const int mod = 1000000007;
int n,a,b,k;
int dp[5005][5005],pre[5005][5005];
signed main(){
cin >> n >> a >> b >> k;
dp[0][a] = 1;
for(int i = a;i<=n;i++)pre[0][i] = 1;
for(int i = 1;i<=k;i++){
for(int j = 1;j<=n;j++){
if(j<b){
dp[i][j] = pre[i-1][(j+b-1)>>1]-dp[i-1][j];
}if(j>b){
dp[i][j] = pre[i-1][n]-pre[i-1][(j+b)>>1]-dp[i-1][j];
}dp[i][j]+=mod,dp[i][j]%=mod;
// cout << dp[i][j] << " ";
}for(int j = 1;j<=n;j++)pre[i][j] = (pre[i][j-1]+dp[i][j])%mod;
// cout << endl;
}cout << pre[k][n] << endl;
return 0;
}
详细
小提示：点击横条可展开更详细的信息
Test #1:
score: 10
Accepted
time: 0ms
memory: 2092kb
input:
98 18 22 94
output:
27076018
result:
ok single line: '27076018'
Test #2:
score: 10
Accepted
time: 0ms
memory: 2072kb
input:
95 94 73 92
output:
748455277
result:
ok single line: '748455277'
Test #3:
score: 10
Accepted
time: 409ms
memory: 390908kb
input:
4674 2740 4172 4983
output:
454585991
result:
ok single line: '454585991'
Test #4:
score: 10
Accepted
time: 426ms
memory: 391792kb
input:
4981 813 4046 4994
output:
226418975
result:
ok single line: '226418975'
Test #5:
score: 10
Accepted
time: 345ms
memory: 377372kb
input:
4595 3757 519 4810
output:
194357577
result:
ok single line: '194357577'
Test #6:
score: 10
Accepted
time: 393ms
memory: 378260kb
input:
4902 277 2317 4821
output:
641852228
result:
ok single line: '641852228'
Test #7:
score: 10
Accepted
time: 436ms
memory: 391468kb
input:
4516 1607 639 4990
output:
973001631
result:
ok single line: '973001631'
Test #8:
score: 10
Accepted
time: 367ms
memory: 364724kb
input:
4823 1127 3840 4648
output:
431104558
result:
ok single line: '431104558'
Test #9:
score: 10
Accepted
time: 398ms
memory: 377928kb
input:
4937 3261 2918 4817
output:
638296884
result:
ok single line: '638296884'
Test #10:
score: 10
Accepted
time: 372ms
memory: 378804kb
input:
4744 135 2414 4828
output:
30641258
result:
ok single line: '30641258'
