online_judge_1091

来源：互联网发布：2015网络歌曲排行榜编辑：程序博客网时间：2024/06/15 14:05

这个题目是深度优先搜索的应用。很有意思，有两点值得注意。一是题目意思很不好理解。。二是下面代码中注释的一行。。初始点可以再次经过，，很坑……

#include <iostream>#include <algorithm>using namespace std;const int Max = 0x07ffffff;int a[7][7];bool mark[7][7];int go[4][2] = {{0,1},{0,-1},{-1,0},{1,0}};int result;int s2, e2;void DFS(int s1, int e1, int sum, int status){    if(s1 == s2 && e1 == e2)    {        result = min(result, sum);        return ;    }    if(sum > result) //这一步剪枝优化十分重要。。学习网上大牛的……        return ;    int t,ts,te;    for(int i=0; i<4; ++i)    {        ts = s1 + go[i][0];        te = e1 + go[i][1];        if(ts<=6&&ts>=1&&te<=6&&te>=1)        {            if(mark[ts][te])                continue;            t = sum + a[ts][te]*status;            mark[ts][te] = true;            DFS(ts, te, t, (a[ts][te]*status)%4+1);            mark[ts][te] = false;        }    }}int main(){    int i,j,n,status;    cin>>n;    int s1,e1;    while(n--)    {        for(i=1; i<7; ++i)        {            for(j=1; j<7; ++j)            {                cin>>a[i][j];                mark[i][j] = false;            }        }        cin>>s1>>e1>>s2>>e2;        result = Max;        s1++;e1++;        s2++;e2++;        mark[s1][e1] = true;        status = 1;        DFS(s1, e1, 0, status);        cout<<result<<endl;    }    return 0;}

之前理解错题意。以为只是简单的一个图求最短路径。。代码谢了好多，也贴下来吧！！！

#include <iostream>#include <vector>using namespace std;const int Max = 0x07ffffff;struct E{    int cost;    int next;};vector<E> edge[37];int main(){    int a[7][7];    int n,i,j,t,c;    int Min;    int s,e,newP;    int Dis[37];    bool mark[37];    cin>>n;    while(n--)    {        for(i=0; i<37; ++i)            edge[i].clear();        for(i=1; i<7; ++i)        {            for(j=1; j<7; ++j)                cin>>a[i][j];        }        t = 1;        for(i=1; i<7; ++i)        {            for(j=1; j<7; ++j)            {                E tmp;                if(i==1)                {                    if(j==1)                    {                        tmp.next = t+1;                        tmp.cost = (a[i][j]*a[i][j+1])%4 + 1;                        edge[t].push_back(tmp);                        tmp.next = t+6;                        tmp.cost = (a[i][j]*a[i+1][j])%4 + 1;                        edge[t].push_back(tmp);                    }                    else if(j==6)                    {                        tmp.next = t+6;                        tmp.cost = (a[i][j]*a[i+1][j])%4 + 1;                        edge[t].push_back(tmp);                        tmp.next = t-1;                        tmp.cost = (a[i][j]*a[i][j-1])%4 + 1;                        edge[t].push_back(tmp);                    }                    else                    {                        tmp.next = t+6;                        tmp.cost = (a[i][j]*a[i+1][j])%4 + 1;                        edge[t].push_back(tmp);                        tmp.next = t-1;                        tmp.cost = (a[i][j]*a[i][j-1])%4 + 1;                        edge[t].push_back(tmp);                        tmp.next = t+1;                        tmp.cost = (a[i][j]*a[i][j+1])%4 + 1;                        edge[t].push_back(tmp);                    }                }                else if(i==6)                {                    if(j==1)                    {                        tmp.next = t+1;                        tmp.cost = (a[i][j]*a[i][j+1])%4 + 1;                        edge[t].push_back(tmp);                        tmp.next = t-6;                        tmp.cost = (a[i][j]*a[i-1][j])%4 + 1;                        edge[t].push_back(tmp);                    }                    else if(j==6)                    {                        tmp.next = t-6;                        tmp.cost = (a[i][j]*a[i-1][j])%4 + 1;                        edge[t].push_back(tmp);                        tmp.next = t-1;                        tmp.cost = (a[i][j]*a[i][j-1])%4 + 1;                        edge[t].push_back(tmp);                    }                    else                    {                        tmp.next = t-6;                        tmp.cost = (a[i][j]*a[i-1][j])%4 + 1;                        edge[t].push_back(tmp);                        tmp.next = t-1;                        tmp.cost = (a[i][j]*a[i][j-1])%4 + 1;                        edge[t].push_back(tmp);                        tmp.next = t+1;                        tmp.cost = (a[i][j]*a[i][j+1])%4 + 1;                        edge[t].push_back(tmp);                    }                }                else                {                    if(j==1)                    {                        tmp.next = t+1;                        tmp.cost = (a[i][j]*a[i][j+1])%4 + 1;                        edge[t].push_back(tmp);                        tmp.next = t+6;                        tmp.cost = (a[i][j]*a[i+1][j])%4 + 1;                        edge[t].push_back(tmp);                        tmp.next = t-6;                        tmp.cost = (a[i][j]*a[i-1][j])%4 + 1;                        edge[t].push_back(tmp);                    }                    else if(j==6)                    {                        tmp.next = t+6;                        tmp.cost = (a[i][j]*a[i+1][j])%4 + 1;                        edge[t].push_back(tmp);                        tmp.next = t-6;                        tmp.cost = (a[i][j]*a[i-1][j])%4 + 1;                        edge[t].push_back(tmp);                        tmp.next = t-1;                        tmp.cost = (a[i][j]*a[i][j-1])%4 + 1;                        edge[t].push_back(tmp);                    }                    else                    {                        tmp.next = t+6;                        tmp.cost = (a[i][j]*a[i+1][j])%4 + 1;                        edge[t].push_back(tmp);                        tmp.next = t-1;                        tmp.cost = (a[i][j]*a[i][j-1])%4 + 1;                        edge[t].push_back(tmp);                        tmp.next = t+1;                        tmp.cost = (a[i][j]*a[i][j+1])%4 + 1;                        edge[t].push_back(tmp);                        tmp.next = t-6;                        tmp.cost = (a[i][j]*a[i-1][j])%4 + 1;                        edge[t].push_back(tmp);                    }                }                t++;            }        }        cin>>i>>j;        s = i*6+j+1;        cin>>i>>j;        e = i*6+j+1;        //到这一步图模型已经建好了。接下来就是用Dijstra算法求解最短路径了        for(i=1; i<37; ++i)        {            mark[i] = false;            Dis[i] = -1;        }        Dis[s] = 0;        mark[s] = true;        newP = s;        for(i=1; i<37; ++i)        {            for(unsigned int j=0; j<edge[newP].size(); ++j)            {                c = edge[newP][j].cost;                t = edge[newP][j].next;                if(mark[t])                    continue;                if(Dis[t] == -1 || Dis[t] > Dis[newP] + c)                    Dis[t] = Dis[newP] + c;            }            Min = Max;            for(int j=1; j<37; ++j)            {                if(mark[j])                    continue;                if(Dis[j] == -1)                    continue;                if(Min > Dis[j])                {                    newP = j;                    Min = Dis[j];                }            }            mark[newP] = true;        }        cout<<Dis[e]<<endl;    }    return 0;}

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