2017 ACM-ICPC Beijing, D - Chinese Checkers

题意

给你一个魔改版的跳棋, 模拟操作, 最后输出局面

做法

用链表建完棋盘后就很简单了. 一开始写起来比较烦, 最后悟到建棋盘其实就是一个描述过程, 你大可用纯粹用代码来描述, 这不可避免大量的讨论; 也可以用数据来描述, 手动输入每个点六个方向的点是谁, 这枯燥的输入绝对无法正确搞定, 那么其实我应该要做的是trade off, 结合数据和代码来描述, 得到了一个比较好写的做法.

#include <bits/stdc++.h>
using namespace std;

struct Cell {
    int r, c; // r: region(1, 2, 3, 4, 5, 6, 0), c: color, occupid by who, 
    Cell *L, *R, *UL, *UR, *LL, *LR;
    Cell() {
        r = c = 0;
        L = R = UL = UR = LL = LR = NULL;
    }
} cells[20 * 20], *row[20], *loc = cells;


Cell*goRight(Cell*x, int d) {
    for (int i = 0; i < d; ++i)
        x = x->R;
    return x;
}

int num[] = {0, 1, 2, 3, 4, 13, 12, 11, 10, 9, 10, 11, 12, 13, 4, 3, 2, 1};
int sp[] = {0, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 5, 1, 1, 1};
int sc[] = {0, 0, 1, 1, 1, 5, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0};

void build() {
    Cell *p, *c;

    for (int i = 1; i <= 17; ++i)
        row[i] = loc++;

    for (int i = 1; i <= 17; ++i) {
        p = row[i];
        for (int j = 1; j <= num[i]; ++j) {
            p->R = loc++;
            if (j != 1)
                p->R->L = p;
            p = p->R;
        }
    }

    for (int i = 2; i <= 17; ++i) {
        p = goRight(row[i - 1]->R, sp[i - 1]);
        c = i == 5 ? goRight(row[i]->R, 4) : row[i]->R;
        while (p && c) {
            c->UR = p;
            p->LL = c;
            p = p->R;
            c = c->R;
        }
    }

    for (int i = 2; i <= 17; ++i) {
        c = goRight(row[i]->R, sc[i]);
        p = i == 14 ? goRight(row[i - 1]->R, 4) : row[i - 1]->R;
        while (p && c) {
            c->UL = p;
            p->LR = c;
            p = p->R;
            c = c->R;
        }
    }

}


void recolor() {
    Cell*p;
    for (int i = 1; i <= 17; ++i) {
        p = row[i]->R;
        while (p) {
            p->c = 0;
            p = p->R;
        }
    }

    for (int i = 1; i <= 4; ++i) {
        p = row[i]->R;
        for (int j = 1; j <= i; ++j) {
            p->c = p->r = 1;
            p = p->R;
        }
    }

    for (int i = 5; i <= 8; ++i) {
        p = row[i]->R;
        for (int j = 4; i - 5 < j; --j) {
            p->c = p->r = 6;
            p = p->R;
        }
        p = goRight(row[i]->R, 9);
        for (int j = 4; i - 5 < j; --j) {
            p->c = p->r = 4;
            p = p->R;
        }
    }

    for (int i = 10; i <= 13; ++i) {
        p = row[i]->R;
        for (int j = 0; j < i - 9; ++j) {
            p->c = p->r = 3;
            p = p->R;
        }
        p = goRight(row[i]->R, 9);
        for (int j = 0; j < i - 9; ++j) {
            p->c = p->r = 5;
            p = p->R;
        }
    }

    for (int i = 14; i <= 17; ++i) {
        p = row[i]->R;
        for (int j = 4; i - 14 < j; --j) {
            p->c = p->r = 2;
            p = p->R;
        }
    }
}

Cell*go(Cell*c, string dir) {
    if (dir == "L")
        return c->L;
    if (dir == "R")
        return c->R;
    if (dir == "UL")
        return c->UL;
    if (dir == "UR")
        return c->UR;
    if (dir == "LL")
        return c->LL;
    return c->LR;
}

vector<pair<bool, Cell*> > path;
int ok_col[7] = {0, 2, 1, 4, 3, 6, 5};

bool sym(int l, int r) {
    for (int i = l, j = r; i < j; ++i, --j)
        if (path[i].first != path[j].first)
            return false;
    if (r < l) return true;
    int cnt = 0;
    for (int i = l; i <= r; ++i)
        if (!path[i].first) ++cnt;
    return cnt > 0;
}

bool ok(int p, int c) {
    if (path[p].second->r == 0 || path[p].second->r == c || ok_col[path[p].second->r] == c) {
        return path[p].first;
    }
    return false;
}

vector<pair<int, int> > pos[7];

int go(Cell*c, string dir, int t) {
    if (!c) return t;
    return go(go(c, dir), dir, t + 1);
}

int main() {
#ifdef lol
    freopen("d.in", "r", stdin);
    freopen("d.out", "w", stdout);
#endif

    build();
    int r, c, n;
    string dir;
    while (cin >> n) {
        recolor();
        int player = 1;
        while (n--) {
            cin >> r >> c >> dir;
            //cout << r << ' ' << c << ' ' << dir << endl;
            Cell*p = row[r], *t;
            for (int i = 0; i < c; ++i)
                if (p)
                    p = p->R;
            if (p && p->c == player) {
                path.clear();
                t = p;
                while (t) {
                    path.push_back(make_pair(t->c == 0, t));
                    t = go(t, dir);
                }
            //    printf("%d\n", (int)path.size());
                t = NULL;
                for (int i = 1; i < (int)path.size(); ++i) {
                    if (sym(1, i - 1) && ok(i, p->c))
                        t = path[i].second;
                }
                if (t != NULL) {
                    swap(t->c, p->c);
            //        puts("ok");
                }
            }
            for (int i = 1; i <= 6; ++i) {
                pos[i].clear();
            }
            for (int i = 1; i <= 17; ++i) {
                p = row[i]->R;
                for (int j = 1; p; p = p->R, ++j) {
                    if (p->c)
                        pos[p->c].push_back(make_pair(i, j));
                }
            }
            player %= 6;
            ++player;
        }
        for (int i = 1; i <= 6; ++i) {
            sort(pos[i].begin(), pos[i].end());
            for (int j = 0; j < (int)pos[i].size(); ++j)
                printf("%d %d ", pos[i][j].first, pos[i][j].second);
            puts("");
        }
    }


    return 0;
}