201413-2 Z字形扫描

实现

#include <cstdio>

#define MAXN 0x1ff

int directions[4][2] = {
    {0,1},  // right
    {1,-1}, // left and down
    {1,0},  // down
    {-1,1}  // right and up
};

int size;

void getDirection(int* dir,int x, int y) {
    if (*dir == 0) {
        if (x == 0) {
            *dir = 1;
        } else {
            *dir = 3;
        }
    } else if (*dir == 1) {
        if (x == size - 1) {
            *dir = 0;
        } else if (y == 0) {
            *dir = 2;
        } else {
            *dir = 1;
        }
    } else if (*dir == 2) {
        if (y == 0) {
            *dir = 3;
        } else {
            *dir = 1;
        }
    } else {
        if (y == size - 1) {
            *dir = 2;
        } else if (x == 0) {
            *dir = 0;
        } else {
            *dir == 3;
        }
    }
}

int map[MAXN][MAXN];

int main() {
    scanf("%d",&size);

    for (int i = 0;i < size;++i) {
        for (int j = 0;j < size;++j) {
            scanf("%d",&map[i][j]);
        }
    }

    int x = 0, y = 0,dir = 0;
    for (int i = 0; i < size;++i) {
        for (int j = 0;j < size;++j) {
            printf("%d ",map[x][y]);
            x += directions[dir][0];
            y += directions[dir][1];
            getDirection(&dir,x,y);
           
        }
    }
}