# UVA1589

``````//
// Created by sixleaves on 16/11/24.
//

#include
#include

int board[11][10] = {0};

#define MAX(x, y) ((x) > (y)? (x) : (y))

bool aviableGPos(int x, int y) {

if (x >= 1 && x <=3 && y >=4 && y <=6) return true;
if (x >= 8 && x <= 10 && y >=4 && y <=6) return true;
return false;
}

bool aviableBoardPos(int x, int y) {

if (x >=1 && x <=10 && y >=1 && y <=9) return true;
return false;
}

bool isleg(int hx, int hy, int gx, int gy) {

// 竖直方向
int d = hx - gx < 0? gx -hx : hx -gx;
if (d == 2) {
// 马再将下面
if (hx > gx) {

if (board[hx - 1][hy] != 0) return true;
return false;
}else {
if (board[hx + 1][hy] !=0) return true;
return false;
}

}else { // 水平方向
d = hy - gy < 0? gy -hy : hy -gy;
if (2 == d) {
// 马在将水平方向的右侧
if (hy > gy) {
if (board[hx][hy - 1] != 0) return true;
return false;
} else {
if (board[hx][hy + 1] != 0) return true;
return false;
}
}
return true;
}

}

// == -1表示该位置不合法. 0表示该位置不会将死, 1表示该位置会被将死
int checkmate(int x, int y, int lastX, int lastY) {

int ischeckmate = 0;
char eatPiece ;
// 将军的位置是合法的
if (!aviableGPos(x, y)) return -1;
else {
// 吃掉棋子或者移动到该位置
eatPiece = board[x][y];
board[x][y] = 0;
}

for (int i = 1; i <= 10; i++) {

for (int j = 1; j <= 9; j++) {

switch (board[i][j]) {
// chariot
case 'R': {

if (x == i) {
int maxC = MAX(j, y);
int minC = j + y - maxC;
ischeckmate = 1;
for (int k = minC + 1; k < maxC; k++) if (board[i][k] != 0) ischeckmate = 0;
}

if (y == j) {
int maxC = MAX(x, i);
int minC = i + x - maxC;
ischeckmate = 1;
for (int k = minC + 1; k < maxC; k++) if (board[k][j] != 0) ischeckmate = 0;
}

// 如果能将死, 则需要悔棋
if (ischeckmate == 1) {

board[x][y] = eatPiece;
return 1;
}

break;
}
case 'H': {

int dx[] = {2, 2, -2, -2, 1, -1, 1, -1};
int dy[] = {1, -1, 1, -1, 2, -2, -2, 2};

for (int k = 0; k < 8; k++) {

int hx = i + dx[k];
int hy = j + dy[k];
if (hx == x && hy == y) {
// check horse leg
ischeckmate = 0;
if (!isleg(i, j, x, y))
ischeckmate = 1;
break;
}

}

if (ischeckmate == 1) {

board[x][y] = eatPiece;
return 1;
}

break;
}
case 'G': {

if (y == j) {
int maxC = MAX(x, i);
int minC = i + x - maxC;
ischeckmate = 1;
for (int k = minC + 1; k < maxC; k++) if (board[k][j] != 0) ischeckmate = 0;
}

if (ischeckmate == 1) {
board[x][y] = eatPiece;
return 1;
}

break;
}
case 'C': {

if (x == i) {
int maxC = MAX(j, y);
int minC = j + y - maxC;
int count = 0;
for (int k = minC + 1; k < maxC; k++) if (board[i][k] != 0) count++;
if (count == 1) ischeckmate = 1;
}

if (y == j) {
int maxC = MAX(x, i);
int minC = i + x - maxC;
int count = 0;
for (int k = minC + 1; k <  maxC; k++) if (board[k][j] != 0) count++;
if (count == 1) ischeckmate = 1;
}

if (ischeckmate == 1) {
board[x][y] = eatPiece;
return 1;
}

break;
}
default:
break;
}

}
}

board[x][y] = eatPiece;
return ischeckmate;

}

char ch;
for (;;) {
ch = getchar();
if (ch != ' ' && ch != '\r' && ch != '\n') return ch;
}
}

int main() {

int n, x,y;

while ((scanf("%d%d%d", &n, &x, &y) == 3) && n && x && y) {

memset(board, 0, sizeof(board));

for (int i = 0; i < n; i++) {
char ch;
int chx, chy;
scanf("%d%d",&chx, &chy);
board[chx][chy] = ch;
}

bool ischeckMate = true;
int dx[] = {1, -1, 0, 0};
int dy[] = {0, 0, 1, -1};

// 先检查是否是fly

for (int i = 0; i < 4; i++) {
// 试走, 如果不是死期, 则证明这步是可以走的.那么不是死局
int flag = checkmate(x + dx[i], y +dy[i], x, y);
if (0 == flag) ischeckMate = false;
}

if (ischeckMate) printf("YES\n");
else printf("NO\n");
}
return 0;
}

``````