代码厌氧

#include<bits/stdc++.h>
using namespace std;

int read(){
	int x=0,f=1;char ch=getchar();
	while(ch<'0'||ch>'9'){if(ch=='-')f=-1;ch=getchar();}
	while(ch>='0'&&ch<='9'){x=x*10+ch-48;ch=getchar();}
	return x*f;
}
int n,m,a[35],mid,ans;
vector<int>b,c;

void dfs1(int i,int res){
	if(i>mid){
		b.push_back(res);
		return;
	}
	dfs1(i+1,(res+a[i])%m);
	dfs1(i+1,res);
}
void dfs2(int i,int res){
	if(i>n){
		c.push_back(res);
		return;
	}
	dfs2(i+1,(res+a[i])%m);
	dfs2(i+1,res);
}

int main(){
	scanf("%d%d",&n,&m);
	for(int i=1;i<=n;i++){
		scanf("%d",&a[i]);
	}
	mid=n>>1;
	dfs1(1,0);
	dfs2(mid+1,0);
	sort(b.begin(),b.end());
	sort(c.begin(),c.end());
	int lb=b.size(),lc=c.size();	
	for(int i=0;i<lb;i++){
		int pos=lower_bound(c.begin(),c.end(),m-b[i])-c.begin()-1;
		ans=max(ans,b[i]+c[pos]);
	}
	ans=max(ans,b[lb-1]+c[lc-1]-m);
	
	cout<<ans<<"\n";
	return 0;
}

输入

35 10
86 66 98 91 61 71 14 58 49 92 13 97 13 22 98 83 85 29 85 41 51 16 76 17 75 25 71 10 87 11 9 34 3 6 4

正确输出

9