hrbust 1181 移动【邻接阵，bfs】

#include<stdio.h>
#include<string.h>

#define INF 0xfffffff
struct point {
	int x;
	int y;
};
int step[301][301];
struct point que[30000001];

int main()
{
	struct point p1, p2;
	while(scanf("%d %d %d %d", &p1.x, &p1.y, &p2.x, &p2.y) != EOF) {
//		memset(step, 0, sizeof(step));
		for(int i = 0; i <= 300; i++) {
			for(int j = 0; j <= 300; j++) {
				step[i][j] = INF;
			}
		}
		step[p1.x][p1.y] = 0;
		struct point *qb, *qe;
		qb = qe = que;
		qe->x = p1.x;
		qe->y = p1.y;
		qe++;
		while(qb < qe) {
			struct point *tmp = qb++;

			if(tmp->x + 2 >= 0 && tmp->x + 2 <= 300 && tmp->y - 1 >= 0 && tmp->y - 1 <= 300 && step[tmp->x][tmp->y]+1 < step[tmp->x + 2][tmp->y - 1]) {
				step[tmp->x + 2][tmp->y - 1] = step[tmp->x][tmp->y] + 1;
				qe->x = tmp->x + 2;
				qe->y = tmp->y - 1;
				qe++;
			}

			if(tmp->x + 2 >= 0 && tmp->x + 2 <= 300 && tmp->y + 1 >= 0 && tmp->y + 1 <= 300 && step[tmp->x][tmp->y]+1 < step[tmp->x + 2][tmp->y + 1]) {
				step[tmp->x + 2][tmp->y + 1] = step[tmp->x][tmp->y] + 1;
				qe->x = tmp->x + 2;
				qe->y = tmp->y + 1;
				qe++;
			}

			if(tmp->x - 2 >= 0 && tmp->x - 2 <= 300 && tmp->y - 1 >= 0 && tmp->y - 1 <= 300 && step[tmp->x][tmp->y]+1 < step[tmp->x - 2][tmp->y - 1]) {
				step[tmp->x - 2][tmp->y - 1] = step[tmp->x][tmp->y] + 1;
				qe->x = tmp->x - 2;
				qe->y = tmp->y - 1;
				qe++;
			}

			if(tmp->x - 2 >= 0 && tmp->x - 2 <= 300 && tmp->y + 1 >= 0 && tmp->y + 1 <= 300 && step[tmp->x][tmp->y]+1 < step[tmp->x - 2][tmp->y + 1]) {
				step[tmp->x - 2][tmp->y + 1] = step[tmp->x][tmp->y] + 1;
				qe->x = tmp->x - 2;
				qe->y = tmp->y + 1;
				qe++;
			}

			if(tmp->x + 1 >= 0 && tmp->x + 1 <= 300 && tmp->y + 2 >= 0 && tmp->y + 2 <= 300 && step[tmp->x][tmp->y]+1 < step[tmp->x + 1][tmp->y + 2]) {
				step[tmp->x + 1][tmp->y + 2] = step[tmp->x][tmp->y] + 1;
				qe->x = tmp->x + 1;
				qe->y = tmp->y + 2;
				qe++;
			}

			if(tmp->x - 1 >= 0 && tmp->x - 1 <= 300 && tmp->y + 2 >= 0 && tmp->y + 2 <= 300 && step[tmp->x][tmp->y]+1 < step[tmp->x - 1][tmp->y + 2]) {
				step[tmp->x - 1][tmp->y + 2] = step[tmp->x][tmp->y] + 1;
				qe->x = tmp->x - 1;
				qe->y = tmp->y + 2;
				qe++;
			}

			if(tmp->x + 1 >= 0 && tmp->x + 1 <= 300 && tmp->y - 2 >= 0 && tmp->y - 2 <= 300 && step[tmp->x][tmp->y]+1 < step[tmp->x + 1][tmp->y - 2]) {
				step[tmp->x + 1][tmp->y - 2] = step[tmp->x][tmp->y] + 1;
				qe->x = tmp->x + 1;
				qe->y = tmp->y - 2;
				qe++;
			}

			if(tmp->x - 1 >= 0 && tmp->x - 1 <= 300 && tmp->y - 2 >= 0 && tmp->y - 2 <= 300 && step[tmp->x][tmp->y]+1 < step[tmp->x - 1][tmp->y - 2]) {
				step[tmp->x - 1][tmp->y - 2] = step[tmp->x][tmp->y] + 1;
				qe->x = tmp->x - 1;
				qe->y = tmp->y - 2;
				qe++;
			}
		}
		printf("%d\n", step[p2.x][p2.y]);
	}
	return 0;
}

　　题目连接：http://acm.hrbust.edu.cn/index.php?m=Status&a=showCode&run_id=44125