UVa #1533 Moving Pegs (习题7-12)

跳棋+黑白棋，模拟大法好

这次的码写的挺丑的，而且速度也很慢，只是摸爬滚打刚刚够AC

Rujia说第七章的习题想达到更好的效果要做10道，现在做了8道。其实中途还做了其他的，但是最终都没能做完或者AC掉

虽然心有不甘，但是毕竟时间有限。。现在只想快点进入第八章，dp和图论还在等着我。。

Run Time: 1.202s

#define UVa  "7-12.1533.cpp"

#include<cstring>
#include<cstdlib>
#include<cstdio>

using namespace std;
//Global Variables. Reset upon Each Case!
int board;
int hole;
const int adj[15][4][6] =
{
{{1,2},{3,5},{6,9},{10,14}},
{{0,2,3,4},{-1,-1,6,8},{-1,-1,10,13}},
{{0,1,4,5},{-1,-1,7,9},{-1,-1,11,14}},
{{1,4,6,7},{0,5,10,12}},
{{1,2,3,5,7,8},{-1,-1,-1,-1,11,13}},
{{2,4,8,9},{0,3,12,14}},
{{3,7,10,11},{1,8,-1,-1},{0,9,-1,-1}},
{{3,4,6,8,11,12},{-1,2,-1,9,-1,-1}},
{{4,5,7,9,12,13},{1,-1,6,-1,-1,-1}},
{{5,8,13,14},{2,7,-1,-1},{0,6,-1,-1}},
{{6,11},{3,12},{1,13},{0,14}},
{{6,7,10,12},{-1,4,-1,13},{-1,2,-1,14}},
{{7,8,11,13},{3,5,10,14}},
{{8,9,12,14},{4,-1,11,-1},{1,-1,10,-1}},
{{9,13},{5,12},{2,11},{0,10}}
};

const int adj_depth[15] = {4,3,3,2,2,2,3,2,2,3,4,3,2,3,4};
const int adj_size[15] = {2, 4, 4, 4, 6, 4, 4, 6, 6, 4, 2, 4, 4, 4, 2};
const int maxstate = 1<<15+10;
int vis[maxstate];
int q[maxstate], d[maxstate], fa[maxstate], act[maxstate][2];
/////

int getDepthPos(int src, int targ, int& d, int& p) {
    for(int i = 0; i < adj_depth[src]; i ++) {
        for(int j = 0; j < adj_size[src]; j ++) {
            if(adj[src][i][j] == targ) {
                d = i; p = j;
                return 1;
            }
        }
    }
    return 0;
}

int movable(int b, int peg, int targdepth, int targpos) {
    for(int i = 0; i < targdepth; i ++) {       //before arrival, there should be no holes.
        if(adj[peg][i][targpos] == -1 || !(b & (1<<adj[peg][i][targpos])) )return 0;
    }
    if(!(b & (1<<adj[peg][targdepth][targpos]))) {
        return 1;
    }
    return 0;
}

int move(int& b, int peg, int targdepth, int targpos) {
    b -= 1<<peg;
    for(int i = 0; i < targdepth; i ++) {
        b -= 1<<adj[peg][i][targpos];               //set to 0 for the positions along the path;
    }
    b |= 1<<adj[peg][targdepth][targpos];
    return 1;
}

void print_ans(int u) {
    if(fa[u] && fa[u] != 1) {
        print_ans(fa[u]);
        printf(" ");
    }
    printf("%d %d", act[u][0]+1, act[u][1]+1);
}

int bfs() {
    int front = 1, rear = 2;
    fa[front] = 0;
    d[front] = 0;
    q[front] = board;
    memset(vis, 0, sizeof(vis));
    vis[board] = 1;
    while(front < rear) {
        int b = q[front];
        if(b == (1<<(hole))){
            printf("%d\n", d[front]);
            print_ans(front);
            printf("\n");
            return 1;
        }
        for(int i = 0; i < 15; i ++) if(b & (1<<i)){    //if there's a peg on the position.
            for(int j = 0; j < 15; j ++) if(!(b & (1<<j))){         //found a hole. (i != j for sure)
                int vd, vp;
                if(getDepthPos(i, j, vd, vp)) if(movable(b, i, vd, vp) && vd){           //
                    int v = b;
                    move(v, i, vd, vp);
                    if(!vis[v]){
                        vis[v] = 1;
                        q[rear] = v;
                        act[rear][0] = i;
                        act[rear][1] = j;
                        fa[rear] = front;
                        d[rear++] = d[front] + 1;
                    }
                }
            }
        }
        front ++;
    }
    return 0;
}

int main() {
    int T;
    scanf("%d", &T);
    while(T--) {
        scanf("%d", &hole);
        hole --;
        board = (1<<15) - 1;
        board ^= (1<<hole);
        if(!bfs()) printf("IMPOSSIBLE\n");
    }
    return 0;
}