UVA 1589:Xiangqi (模拟 Grade D)

题目：

象棋，黑棋只有将，红棋有帅车马炮。问是否死将。

思路：

对方将四个方向走一步，看看会不会被吃。

代码：

很难看……WA了很多发，还越界等等。

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

char graph[13][13];
int go[4][2] = {{1,0},{0,1},{-1,0},{0,-1}};

bool inBlackPalace(int x, int y) {
    return 4 <= y && y <= 6 && 1 <= x && x <= 3;
}

bool inChess(int x, int y) {
    return 1 <= x && x <= 10 && 1 <= y && y <= 9;
}

bool goG(int x, int y) {
    for (int i = x-1; i >= 1; i--) {
        if (graph[i][y]) {
            return graph[i][y] == 'B';
        }
    }
    return false;
}

bool goR(int x, int y) {
    for (int i = x-1; i >= 1; i--) {
        if (graph[i][y]) {
            if (graph[i][y] == 'B') return true;
            break;
        }
    }
    for (int i = x+1; i <= 10; i++) {
        if (graph[i][y]) {
            if (graph[i][y] == 'B') return true;
            break;
        }
    }
    for (int j = y-1; j >= 1; j--) {
        if (graph[x][j]) {
            if (graph[x][j] == 'B') return true;
            break;
        }
    }
    for (int j = y+1; j <= 9; j++) {
        if (graph[x][j]) {
            if (graph[x][j] == 'B') return true;
            break;
        }
    }
    return false;
}

int can_move(int x,int y,int w)
{
    if(w==1) if(x<1||x>3||y<4||y>6) return 0;
    if(w==2) if(x<1||x>10||y<1||y>9) return 0;
    return 1;
}

bool goH(int x, int y) {
    for (int i = 0; i < 4; i++) {
        int nx = x + go[i][0];
        int ny = y + go[i][1];
        if (1 <= nx && nx <= 10 && 1 <= ny && ny <= 9) {
            if (graph[nx][ny] == 0) {
                if (inChess(nx+go[i][0]+go[i][1],ny+go[i][1]+go[i][0]))
                if (graph[nx+go[i][0]+go[i][1]][ny+go[i][1]+go[i][0]] == 'B') return true;

                if (inChess(nx+go[i][0]-go[i][1],ny+go[i][1]-go[i][0]))
                if (graph[nx+go[i][0]-go[i][1]][ny+go[i][1]-go[i][0]] == 'B') return true;
            }
        }
    }
    return false;
}

bool goC(int x, int y) {
    bool first = true;
    for (int i = x-1; i >= 1; i--) {
        if (graph[i][y]) {
            if (first) {
                first = false;
            } else {
                if (graph[i][y] == 'B') return true;
                break;
            }
        }
    }
    first = true;
    for (int i = x+1; i <= 10; i++) {
        if (graph[i][y]) {
            if (first) {
                first = false;
            } else {
                if (graph[i][y] == 'B') return true;
                break;
            }
        }
    }

    first = true;
    for (int j = y-1; j >= 1; j--) {
        if (graph[x][j]) {
            if (first) {
                first = false;
            } else {
                if (graph[x][j] == 'B') return true;
                break;
            }
        }
    }
    first = true;
    for (int j = y+1; j <= 9; j++) {
        if (graph[x][j]) {
            if (first) {
                first = false;
            } else {
                if (graph[x][j] == 'B') return true;
                break;
            }
        }
    } 
    return false;
}

bool goo(int x, int y) {
    switch(graph[x][y]) {
        case 'G': return goG(x,y); 
        case 'R': return goR(x,y); 
        case 'H': return goH(x,y); 
        case 'C': return goC(x,y); 
    }

    return false;
}

char ch[200];
int main() {
    int n;
    while (scanf("%d", &n) != EOF) {
        int bx, by;
        scanf("%d%d", &bx, &by);
        if (n == 0 && bx == 0 && by == 0) break;

        memset(graph, 0, sizeof(graph));

        for (int i = 0; i < n; i++) {
            int x, y;
            scanf("%s%d%d", ch, &x, &y);
            graph[x][y] = ch[0];
        }

        bool flag = false;
        for (int way = 0; way < 4; way++) {
            int nx = bx + go[way][0];
            int ny = by + go[way][1];
            if (!inBlackPalace(nx, ny)) continue;
            char tmp = graph[nx][ny];
            graph[nx][ny] = 'B';
            bool ok = true;
            for (int i = 1; i <= 10 && ok; i++) {
                for (int j = 1; j <= 9 && ok; j++) {
                    if (graph[i][j]) {
                        if (goo(i,j)) ok = false;
                    }
                }
            }

            graph[nx][ny] = tmp;
            if (ok) {
                flag = true;
                break;
            }
        }

        puts(flag?"NO":"YES");
    }
    return 0;
}