比赛 |
NOIP2023模拟赛2 |
评测结果 |
MMMMMMMMMMMMMMMM |
题目名称 |
魔药 |
最终得分 |
0 |
用户昵称 |
┭┮﹏┭┮ |
运行时间 |
0.000 s |
代码语言 |
C++ |
内存使用 |
0.00 MiB |
提交时间 |
2023-11-14 12:56:22 |
显示代码纯文本
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const long long N = 4e3+10,mod = 1e9+7;
int n,m,k;
ll s[1000010] = {0,1},f[N][N],ans,g[N][N];
char c[1000010];
long long C(int x,int y){
return s[x] / s[x-y] / s[y] % mod;
}
int u[1000010];
bool check(){
int s = 1;
for(int i = 2;i <= n;i++)
if(u[i] != u[i-1])s++;
return (s == m);
}
void sou(int x,int cnt){
if(x == n+1){
if(cnt == k)
if(check()){
ans = (ans + 1) % mod;
// for(int i = 1;i <= n;i++)cout<<u[i]<<' ';
// cout<<endl;
}
return;
}
u[x] = 1;
sou(x+1,cnt+1);
u[x] = 0;
sou(x+1,cnt);
}
int main(){
freopen("sleeping.in","r",stdin);
freopen("sleeping.out","w",stdout);
scanf("%lld%lld%s",&n,&m,c+1);
for(int i = 1;i <= n;i++)if(c[i] == '1')k++;
for(int i = 2;i <= n;i++)s[i] = s[i-1] * i % mod;
if(n <= 16){
sou(1,0);
long long s = C(n,m) - ans;
if(s < 0)s += mod;
printf("%lld %lld\n",ans,s);
return 0;
}
if(m > n){
printf("0 %lld\n",C(n,k));
return 0;
}
for(int i = 1;i <= n;i++){
f[i][1] = 1;
g[i][1] = f[i][1] + g[i-1][1];
}
for(int i = 2;i <= max(k,m);i++)
for(int j = 1;j <= min(i,m);j++){
// for(int l = 1;l <= i;l++)
// f[i][j] += f[i-l][j-1];
f[i][j] += g[i-1][j-1];
g[i][j] = f[i][j] + g[i-1][j];
}
if(m % 2 == 0)ans = 2 * f[k][m/2] * f[n-k][m/2] % mod;
else ans = (f[k][m/2] * f[n-k][m/2+1]) % mod + (f[k][m/2+1] * f[n-k][m/2]) % mod;
// cout<<ans<<endl;
long long s = C(n,m) - ans;
if(s < 0)s += mod;
printf("%lld %lld\n",ans,s);
return 0;
}