HDU4121 Xiangqi

#include 
#include 
#include 
#include 
using namespace std;
struct point
{
    int x,y;
}g[10], r[10], h[10], c[10]; //bg:black general
int gcount, rcount, hcount, ccount;
const int dx[] = {-1, 0, 1, 0};
const int dy[] = {0, 1, 0, -1};

const int hx[] = {-2, -2, -1, 1, 2, 2, 1, -1};
const int hy[] = {1, -1, 2, 2, 1, -1, -2, -2};
bool map[10][10]; //红旗子

//将是否在范围内
bool isValid(int x, int y)
{
    return y >= 4 && y <= 6 && x >= 1 && x <= 3;
}

//[a,y]到[b,y]的棋子个数（不含端点）
int betweenX(int y, int a, int b)
{
    int sum = 0;
    if (a < b)
    {
        for (int i = a + 1; i < b; i++)
        {
            if (map[i][y]) sum++;
        }
    }
    else
    {
        for (int i = b + 1; i < a; i++)
        {
            if (map[i][y]) sum++;
        }
    }
    return sum;
}

//[x,a]到[x,b]的棋子个数（不含端点）
int betweenY(int x, int a, int b)
{
    int sum = 0;
    if (a < b)
    {
        for (int i = a + 1; i < b; i++)
        {
            if (map[x][i]) sum++;
        }
    }
    else
    {
        for (int i = b + 1; i < a; i++)
        {
            if (map[x][i]) sum++;
        }
    }
    return sum;
}

//将的新位置newbg是否会被红方飞将
bool isSafeGeneral(point const &newbg;)
{
    //其实只有一个嘛
    for (int i = 0; i < gcount; i++)
    {
        if (newbg.y == g[i].y)
        {
            if (betweenX(newbg.y, newbg.x, g[i].x) == 0) return false;
        }
    }
    return true;
}

//是否会被车吃（中间没有其他棋子）
bool isSafeChariot(point const &newbg;)
{
    for (int i = 0; i < rcount; i++)
    {
        if (newbg.x == r[i].x && newbg.y == r[i].y) continue; //这就是吃掉了
        if (newbg.x == r[i].x)
        {
            if (betweenY(newbg.x, newbg.y, r[i].y) == 0) return false;
        }
        if (newbg.y == r[i].y)
        {
            if (betweenX(newbg.y, newbg.x, r[i].x) == 0) return false;
        }
    }
    return true;
}

//是否会被炮打（中间棋子为1）
bool isSafeCannon(point const &newbg;)
{
    for (int i = 0; i < ccount; i++)
    {
        if (newbg.x == c[i].x && newbg.y == c[i].y) continue; //这就是吃掉了
        if (newbg.x == c[i].x)
        {
            if (betweenY(newbg.x, newbg.y, c[i].y) == 1) return false;
        }
        if (newbg.y == c[i].y)
        {
            if (betweenX(newbg.y, newbg.x, c[i].x) == 1) return false;
        }
    }
    return true;
}

bool isSafeHorse(point const &newbg;)
{
    int newx, newy;
    for (int i = 0; i < hcount; i++)
    {
        for (int j = 0; j < 8; j++)
        {
            newx = h[i].x + dx[j / 2];
            newy = h[i].y + dy[j / 2];
            if (map[newx][newy]) continue; //别马腿
            newx = h[i].x + hx[j];
            newy = h[i].y + hy[j];
            if (newx == newbg.x && newy == newbg.y) return false;
        }
    }
    return true;
}

//如果不被将，返回真
bool check(point const &newbg;)
{
    return isSafeGeneral(newbg) && isSafeCannon(newbg) && isSafeHorse(newbg) && isSafeChariot(newbg);
}

int main()
{
    int n;
    char ch;
    int a, b;
    while (true)
    {
        point bg, newbg; //bg:black general
        gcount = 0, rcount = 0, hcount = 0, ccount = 0;
        memset(map, 0, sizeof(map));
        bool checkmate = true;
        cin >> n >> bg.x >> bg.y;
        if (!n) break;
        for (int i = 0; i < n; i++)
        {
            cin >> ch >> a >> b;
            map[a][b] = true;
            if (ch == 'G')
            {
                g[gcount].x = a;
                g[gcount].y = b;
                gcount++;
            } else
            if (ch == 'R')
            {
                r[rcount].x = a;
                r[rcount].y = b;
                rcount++;
            } else
            if (ch == 'H')
            {
                h[hcount].x = a;
                h[hcount].y = b;
                hcount++;
            } else
            if (ch == 'C')
            {
                c[ccount].x = a;
                c[ccount].y = b;
                ccount++;
            }
        }
        //不考虑飞将也能过
        /*
        if (!isSafeGeneral(bg))
        {
            puts("NO");
            continue;
        }
        */
        //将的四个方向
        for (int i = 0; i < 4; i++)
        {
            newbg.x = bg.x + dx[i];
            newbg.y = bg.y + dy[i];
            if (!isValid(newbg.x, newbg.y)) continue;
            if (check(newbg))
            {
                checkmate = false;
                break;
            }
        }
        if (checkmate) puts("YES");
        else puts("NO");
    }
    return 0;
}