【习题 7-3 UVA - 211】The Domino Effect

最新推荐文章于 2025-09-11 18:44:42 发布

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最新推荐文章于 2025-09-11 18:44:42 发布

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文章标签：数据结构与算法

原文链接：http://www.cnblogs.com/AWCXV/p/8110739.html

本文通过深度搜索算法解决了一个布局填充问题，旨在寻找所有可能的填充方案，使得每行每列都被完全填充，同时确保每个格子只被使用一次。

【链接】我是链接,点我呀:)
【题意】

在这里输入题意

【题解】

每次搜素要往下还是要往右摆。
然后维护一下让每个下标只出现一次就可以了。
=>作为剪枝条件

【代码】

/*
    1.Shoud it use long long ?
    2.Have you ever test several sample(at least therr) yourself?
    3.Can you promise that the solution is right? At least,the main ideal
    4.use the puts("") or putchar() or printf and such things?
    5.init the used array or any value?
    6.use error MAX_VALUE?
    7.use scanf instead of cin/cout?
    8.whatch out the detail input require
*/
/*
    一定在这里写完思路再敲代码!!!
    爆搜。
    把每一行、每一列都排满。
    然后枚举当前格子是往下排还是往右排
*/
#include <bits/stdc++.h>
using namespace std;

const int N = 10;

int a[N][N];
int bo[N][N],now[N][N];
int cnt[100],ans;

void Init(){
    int cnt = 1;
    for (int i = 0;i <= 6;i++){
        for (int j = i;j <= 6;j++){
            bo[i][j] = cnt++;
        }
    }
}

bool out(){
    for (int i = 1;i <=7;i++){
        for (int j = 1;j <= 8;j++)
            cout <<setw(4)<<now[i][j];
        cout << endl;
    }
    cout << endl << endl;
    return true;
}

void dfs(int x,int y){
    if (y==9){
        if (x==7){
            ans++;
            out();
            return;
        }
        dfs(x+1,1);
        return;
    }
    if (now[x][y]!=0){
        dfs(x,y+1);
        return;
    }
    //向下
    if (x+1<=7){
        int tx = min(a[x+1][y],a[x][y]),ty = max(a[x+1][y],a[x][y]);
        now[x+1][y] = now[x][y] = bo[tx][ty];
        cnt[bo[tx][ty]]++;
        if (cnt[bo[tx][ty]]==1)dfs(x,y+1);
        cnt[bo[tx][ty]]--;
        now[x+1][y] = now[x][y] = 0;
    }
    //向右
    if (y+1<=8 && now[x][y+1]==0){
        int tx = min(a[x][y+1],a[x][y]),ty = max(a[x][y+1],a[x][y]);
        now[x][y+1] = now[x][y] = bo[tx][ty];
        cnt[bo[tx][ty]]++;
        if (cnt[bo[tx][ty]]==1)dfs(x,y+1);
        cnt[bo[tx][ty]]--;
        now[x][y+1] = now[x][y] = 0;
    }
}

int main(){
    #ifdef LOCAL_DEFINE
        freopen("rush_in.txt", "r", stdin);
    #endif
    ios::sync_with_stdio(0),cin.tie(0);
    Init();
    int Kase = 0;
    while (cin >> a[1][1]){
        if (Kase>0){
            cout << endl<<endl<<endl<<endl<<endl;
        }
        ans = 0;
        for (int j = 2;j <= 8;j++) cin >> a[1][j];
        for (int i = 2;i <= 7;i++)
            for (int j = 1;j <= 8;j++)
                cin >> a[i][j];

        cout <<"Layout #"<<++Kase<<":"<<endl<<endl<<endl;
        for (int i = 1;i <= 7;i++){
            for (int j = 1;j <= 8;j++){
                cout <<setw(3)<<a[i][j];
            }
            cout << endl;
        }
        cout << endl;
        cout <<"Maps resulting from layout #"<<Kase<<" are:"<<endl<<endl<<endl;
        dfs(1,1);
        cout <<"There are "<<ans<<" solution(s) for layout #"<<Kase<<"."<<endl;
    }
    return 0;
}

转载于:https://www.cnblogs.com/AWCXV/p/8110739.html