nyoj 21 三个水杯

最新推荐文章于 2019-03-04 20:47:12 发布

原创最新推荐文章于 2019-03-04 20:47:12 发布 · 956 阅读

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具体有图参考：http://blog.youkuaiyun.com/code_pang/article/details/7802944

#include <stdio.h>
#include <string.h>
#include<iostream>
#include <queue>
using namespace std;

int visit[100][100][100];

typedef struct state {
    int state[3];
    int step;
} State;

int target[3], begin[3];

//与目标对比，符合目标返回1，否则返回0
int reachTarget(State cup) {
    for(int i=0; i<3; i++) {
        if(cup.state[i] != target[i])
            return 0;
    }
    return 1;
}

//curr 向dest倒水
void pourWater(int dest, int curr, State &cup) {
    int water = begin[dest] - cup.state[dest]; //dest杯子剩余容量
    if(cup.state[curr] >= water) {
        cup.state[curr] -= water;
        cup.state[dest] += water;
    }
    else {
        cup.state[dest] += cup.state[curr];
        cup.state[curr] = 0;
    }
}

//广搜水杯状态
int bfs() {
    State now;
    memset(visit, 0, sizeof(visit));
    now.state[0] = begin[0];
    now.state[1] = now.state[2] = 0;
    now.step = 0;
    
    queue <State> waterstate;
    waterstate.push(now);
    //标记
    visit[now.state[0]][now.state[1]][now.state[2]] = 1;

    while(!waterstate.empty()) {
        State temp = waterstate.front();
        waterstate.pop();
        
        if(reachTarget(temp))
            return temp.step;
        //简化为一个杯子想另一个杯子倒水
        for(int i=0; i<3; i++) {
            for(int j=0; j<3; j {

                int k = (i+j)%3;
                if(temp.state[i] !=0 && temp.state[k] < begin[k]) {
                    State newT = temp;
                    pourWater(k, i, newT);
                    newT.step = temp.step + 1;
                    if(!visit[newT.state[0]][newT.state[1]][newT.state[2]]) {
                        visit[newT.state[0]][newT.state[1]][newT.state[2]] = 1;
                        waterstate.push(newT);
                    }
                }
            }
        }
    }
   return -1; 
}

int main(void) {
    int t;
    scanf("%d", &t);

    while(t--) {
        scanf("%d%d%d", &begin[0], &begin[1], &begin[2]);
        scanf("%d%d%d", &target[0], &target[1], &target[2]);
        printf("%d\n", bfs());
    }

    return 0;
}

oj给的最优代码：

 
#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#include<bitset>
using namespace std;
#define CLR(arr,val) memset(arr,val,sizeof(arr))
bitset<1000000> Hash;
const int MAX_STEP=100000;
int WQ[MAX_STEP][4],Goal[3],Cap[3],goalval;
int head=0,tail=0;
void movw(int numfrom,int numto,int other)
{
	int total=WQ[head][numfrom]+WQ[head][numto];
	WQ[tail][other]=WQ[head][other];
	WQ[tail][3]=WQ[head][3]+1;
	if(total>Cap[numto])
	{
		WQ[tail][numfrom]=total-Cap[numto];
		WQ[tail][numto]=Cap[numto];
	}
	else
	{
		WQ[tail][numfrom]=0;
		WQ[tail][numto]=total;
	}
	int hashval=WQ[tail][0]*10000+WQ[tail][1]*100+WQ[tail][2];
	if(hashval==goalval) throw WQ[head][3]+1;
	if(WQ[head][numfrom]!=0 && !Hash[hashval]) 
	{
		Hash[hashval]=true;
		if(++tail==MAX_STEP) tail=0;
	}
}
int main()
{
	int t;
	scanf("%d",&t);
	while(t--)
	{
		Hash.reset();
		scanf("%d%d%d%d%d%d",&Cap[0],&Cap[1],&Cap[2],&Goal[0],&Goal[1],&Goal[2]);
		head=0,tail=0,goalval=Goal[0]*10000+Goal[1]*100+Goal[2];
		if(Goal[1]==0 && Goal[2]==0 && Goal[0]==Cap[0]) {puts("0");continue;}
		WQ[tail][0]=Cap[0];WQ[tail][1]=0;WQ[tail][2]=0;WQ[tail][3]=0;
		++tail;
		try{
			while(head!=tail)
			{
				movw(0,1,2);movw(1,2,0);movw(0,2,1);movw(1,0,2);movw(2,1,0);movw(2,0,1);
				if(++head==MAX_STEP) head=0;
			}
			puts("-1");
		}catch(int step)
		{
			printf("%d\n",step);
		}
	}
}