过河（bfs）

RunID: 646956
UserID: handsomecui
Submit time: 2015-12-10 20:23:59
Language: C++
Length: 1393 Bytes.
Result: Accepted

#include<iostream>
#include<cstdio>
#include<cmath>
#include<cstring>
#include<algorithm>
#include<vector>
#include<queue>
#include<stack>
#include<map>
using namespace std;
const int INF=0x3f3f3f3f;
const double PI=acos(-1.0);
typedef long long LL;
#define mem(x,y) memset(x,y,sizeof(x))
#define PI(x) printf("%d",x)
#define PL(x) printf("%lld",x)
#define SI(x) scanf("%d",&x)
#define SL(x) scanf("%lld",&x)
#define P_ printf(" ")
#define T_T while(T--)
struct Node{
	int nw,ns,r,t;
};
int vis[2][210][210];
void bfs(int x,int y,int n){
	queue<Node>dl;
	mem(vis,0);
	Node a,b;
	a.ns=x;a.nw=y;a.t=0;a.r=0;
	dl.push(a);
	vis[0][x][y]=1;
	int cur=0;
	while(!dl.empty()){
		a=dl.front();
		dl.pop();
	//	printf("/******/\n");
		for(int i=0;i<=a.ns;i++){
			for(int j=0;j<=a.nw;j++){
				b.ns=x-a.ns+i;
				b.nw=y-a.nw+j;
				b.t=a.t+1;
				b.r=a.r^1;
				if(i+j==0)continue;
				if(i+j>n)continue;
				if(i&&i<j)continue;
				if(b.ns&&b.ns<b.nw)continue;
				if(a.ns-i<a.nw-j&&(a.ns-i))continue;
				if(vis[b.r][b.ns][b.nw])continue;
			//	printf("%d %d\n",i,j);
				if(b.ns==x&&b.nw==y&&b.r==1){
					printf("%d\n",b.t);
					return;
				}
				vis[b.r][b.ns][b.nw]=1;
				dl.push(b);
			}
		}
	}
	puts("-1");return;
}
int main(){
	int x,y,n;
	while(~scanf("%d%d%d",&x,&y,&n)){
		bfs(x,y,n);
	}
	return 0;
}