最小长度电路板排列问题一

#include <iostream>
#include <fstream>
#include <queue>
#include <algorithm>
using namespace std;

const int MAX = 50;
int p[MAX][MAX];
int bestx[MAX];
int n, m; //电路板数，连接块数

class Node
{
public:
    int dep;  //当前深度
    int cd;   //当前排列长度
    int *x;   //存储当前排列x[1:dep]
    int *low;  //电路块中最左边电路板
    int *high; //电路块中最右边电路板

    Node()
    {
        cd = 0;
        dep = 0;
        high = new int[m+1];
        low = new int[m+1];
        x = new int[n+1];
    }

    int len()  //计算当前排列最小长度
    {
        int temp = 0;
        for(int j=1; j<=m; j++)
        {
            if(low[j]<=n && high[j]>0 && temp<high[j]-low[j])
                temp = high[j] - low[j];
        }
        return temp;
    }
};


int search()
{
    queue<Node> q;
    Node enode;
    int bestd = n + 1;
    int i, j;
    for(j=1; j<=m; j++)
    {
        enode.high[j] = 0;
        enode.low[j] = n + 1;
    }
    for(i=1; i<=n; i++)
        enode.x[i] = i;
    while(true)
    {
        if(enode.dep == n-1) //仅一个儿子结点，已经排完n-1个电路板，现在排最后一个
        {
            for(int j=1; j<=m; j++)
                if(p[ enode.x[n] ][j]>0 && n>enode.high[j]) 
                    enode.high[j] = n;
            enode.cd = enode.len();
            if(enode.cd < bestd)
            {
                bestd = enode.cd; 
                copy(enode.x, enode.x+n+1, bestx);  
            }
        }
        else
        {
            int cur = enode.dep + 1;
            for(i=enode.dep+1; i<=n; i++)  //产生当前扩展结点的所有儿子结点
            {
                Node now;
                for(int j=1; j<=m; j++)
                {
                    now.low[j] = enode.low[j];
                    now.high[j] = enode.high[j];
                    if(p[ enode.x[i] ][j] > 0)
                    {
                        if(cur < now.low[j])
                            now.low[j] = cur;
                        if(cur > now.high[j])
                            now.high[j] = cur;
                    }
                }
                now.cd = now.len();
                if(now.cd < bestd)
                {
                    now.dep = enode.dep + 1;
                    copy(enode.x, enode.x+n+1, now.x);
                    now.x[now.dep] = enode.x[i];     //相当于回溯中的swap(x[dep], x[i])
                    now.x[i] = enode.x[now.dep];
                    q.push(now); 
                }
            }
        }
        if(q.empty())
            break;
        else
        {
            enode = q.front();  //下一层扩展结点
            q.pop();
        }
    }
    return bestd;
}

int main()
{
    ifstream fin("电路板.txt");
    cout << "输入电路板个数：";
    fin >> n; cout << n;
    cout << "\n输入连接块个数：";
    fin  >> m; cout << m;
    cout << "\n输入矩阵：\n";
    int i, j; 
    for(i=1; i<=n; i++)
    {
        for(j=1; j<=m; j++)
        {
            fin >> p[i][j];  
            cout << p[i][j] << " ";
        }
        cout << endl;
    }

    cout << "\n排列的最小长度为：" << search();
    cout << "\n最佳排列为：\n" ;
    for(i=1; i<=n; i++)
        cout << bestx[i] << " ";

    cout << endl;
    cout << endl;
    fin.close();
    return 0;
}