[水+dfs] poj 2034 Anti-prime Sequences

#include"cstdlib"
#include"cstdio"
#include"cstring"
#include"cmath"
#include"queue"
#include"algorithm"
#include"iostream"
#include"map"
#include"stack"
#include"vector"
#define ll __int64
#define inf -999999999999999999LL
using namespace std;
#define MAXN 100007
bool mark[MAXN];
int ss[MAXN/3],sscnt;
int n,m,d,f;
int sum[1234],a[1234],used[1234];
void ssb()
{
    sscnt=0;
    memset(mark,false,sizeof(mark));
    mark[0]=mark[1]=true;
    for(int i=2; i<=MAXN; i++)
    {
        if(!mark[i])
        {
            for(int j=i+i; j<=MAXN; j+=i) mark[j]=true;
            ss[sscnt++]=i;
        }
    }
    return ;
}
void dfs(int x)
{
    if(f) return;
    if(x>m-n+1)
    {
        f=1;
        return ;
    }
    for(int i=n;i<=m;i++)
    {
        if(!used[i])
        {
            int kx=1;
            for(int j=2;j<=d && x-j>=0;j++)
            {
                if(mark[sum[x-1]-sum[x-j]+i]==false) kx=0;
            }
            if(!kx) continue;
            sum[x]=sum[x-1]+i;
            a[x]=i;
            used[i]=1;
            dfs(x+1);
            if(f) return;
            used[i]=0;
        }
    }
}
int main()
{
    ssb();
    while(scanf("%d%d%d",&n,&m,&d),(n+m+d))
    {
        f=0;
        memset(sum,0,sizeof(sum));
        memset(used,0,sizeof(used));
        dfs(1);
        if(!f) puts("No anti-prime sequence exists.");
        else  for(int i=1;i<=m-n+1;i++) printf(i==m-n+1?"%d\n":"%d,",a[i]);
    }
    return 0;
}