C 阿宁的大背包
代码
点击查看代码
#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#include<cmath>
#include<vector>
#include<queue>
using namespace std;
#define X first
#define Y second
typedef pair<int,int> pii;
typedef long long LL;
const char nl = '\n';
const int N = 1e3+10;
const int M = 1e6+10;
const int mod = 1e9+7;
int n;
LL a[N],b[N];
LL ans;
void solve(){
cin >> n;
int nt = n;
if(n % 2 == 0){
int i = n / 2,j = n / 2 + 1;
while(n){
if(n % 2){
a[i] = n;
i --;
}
else{
a[j] = n;
j ++;
}
n --;
}
}
else{
a[n / 2 + 1] = n;
n -= 1;
int i = n / 2,j = n / 2 + 2;
while(n){
if(n % 2){
a[i] = n;
i --;
}
else{
a[j] = n;
j ++;
}
n --;
}
}
for(int i = 1; i <= nt; i ++ )b[i] = a[i];
for(int i = 1; i < nt; i ++ ){
for(int j = 1; j <= nt - i; j ++ ){
a[j] = (a[j] + a[j + 1])%mod;
}
}
cout << a[1] << nl;
for(int i = 1; i <= nt; i ++ )cout << b[i] << " ";
}
int main(){
ios::sync_with_stdio(false);
cin.tie(0),cout.tie(0);
solve();
}
构造(简化写法)
点击查看代码
int p1=0,p2=n+1;
for(int i=1;i<=n;i++){
if(i&1)a[++p1]=i; //奇数
else a[--p2]=i;
}