dfs

原文链接：https://www.luogu.com.cn/problem/P1215

AC代码：

#include<iostream>
#include<string.h>
#include<vector>
#include<set>
#include<algorithm>
using namespace std;
int a,b,c,visit[25][25][25];
set<int> se;
void dfs(int x,int y,int z){
	int i,j;//cout<<x<<" "<<y<<" "<<z<<endl;
	visit[x][y][z]=1;
	if(x==0){
		se.insert(z);
	}
	if(z>0){
		if(y<b&&visit[x][y+((b-y)>z?z:(b-y))][z-((b-y)>z?z:(b-y))]==0){
			dfs(x,y+((b-y)>z?z:(b-y)),z-((b-y)>z?z:(b-y)));
		}
		if(x<a&&visit[x+((a-x)>z?z:(a-x))][y][z-((a-x)>z?z:(a-x))]==0){
			dfs(x+((a-x)>z?z:(a-x)),y,z-((a-x)>z?z:(a-x)));
		}
	}
	if(y>0){
		if(z<c&&visit[x][y-(y>(c-z)?(c-z):y)][z+(y>(c-z)?(c-z):y)]==0){
			dfs(x,y-(y>(c-z)?(c-z):y),z+(y>(c-z)?(c-z):y));
		}
		if(x<a&&visit[x+(y>(a-x)?(a-x):y)][y-(y>(a-x)?(a-x):y)][z]==0){
			dfs(x+(y>(a-x)?(a-x):y),y-(y>(a-x)?(a-x):y),z);
		}
	} 
	if(x>0){
		if(y<b&&visit[x-(x>(b-y)?(b-y):x)][y+(x>(b-y)?(b-y):x)][z]==0){
			dfs(x-(x>(b-y)?(b-y):x),y+(x>(b-y)?(b-y):x),z);
		}
		if(z<c&&visit[x-(x>(c-z)?(c-z):x)][y][z+(x>(c-z)?(c-z):x)]==0){
			dfs(x-(x>(c-z)?(c-z):x),y,z+(x>(c-z)?(c-z):x));
		}
	}
}
int main(){
	int i,j;
	cin>>a>>b>>c;
	memset(visit,0,sizeof(visit));
	dfs(0,0,c);
	for(set<int>::iterator it=se.begin();it!=se.end();it++){
		cout<<*it<<" ";
	}
	return 0;
}