迭代加深搜索模版

#include<iostream>
#include<cstdio>
#include<cstring>
#include<string>
#include<cmath>
#include<cstdlib>
#include<algorithm>
using namespace std;
#define INF 0x7fffffff
int n,m,ans,a[20],rest[20];
void dfs(int x,int num)
{
    if(num>=ans) return ;
    if(x==n+1)
    {
        ans=min(ans,num);
        return ;
    }
    for(int i=1;i<=num;i++)
    {
        if(a[x]+rest[i]<=m)
        {
            rest[i]+=a[x];
            dfs(x+1,num);
            rest[i]-=a[x];
        }
    }
    rest[num+1]+=a[x];
    dfs(x+1,num+1);
    rest[num+1]-=a[x];
    return ;
}
int main()
{
    scanf("%d%d",&n,&m);
    for(int i=1;i<=n;i++)
        scanf("%d",&a[i]);
    ans=INF;
    dfs(1,1);
    printf("%d\n",ans);
    return 0;
}