P5731 【深基5.习6】蛇形方阵

R36471603

problem/P5731/P5731.cpp

@@ -0,0 +1,64 @@
+// R36471603
+
+#include<bits/stdc++.h>
+
+using namespace std;
+
+int n, k, a[15][15], ax, ay;
+
+
+int main() {
+    k = ax = 1;
+
+    scanf("%d", &n);
+    
+    /**
+     * ax, ay+1 -> 右侧
+     * ax, ay-1 -> 左侧
+     * ax+1, ay -> 下方
+     * ax-1, ay -> 上方
+     * 
+     * 0 --- 1 ---------- ay ----------> n
+     * | +------+------+------+------+------+
+     * 1 |      |      | ax-1 |      |      |
+     * | |      |      |  ay  |      |      |
+     * | +------+------+------+------+------+
+     * a |      |  ax  |  ax  |  ax  |      |
+     * x |      | ay-1 |  ay  | ay+1 |      |
+     * | +------+------+------+------+------+
+     * | |      |      | ax+1 |      |      |
+     * | |      |      |  ay  |      |      |
+     * | +------+------+------+------+------+
+     * | |      |      |      |      |      |
+     * | |      |      |      |      |      |
+     * | +------+------+------+------+------+
+     * | |      |      |      |      |      |
+     * n |      |      |      |      |      | n
+     *   +------+------+------+------+------+
+     *                                   n
+     */
+
+    while(k <= n*n) {
+        while(ay < n && !a[ax][ay+1]) { // 右侧  不过边界 && 未填数
+            a[ax][++ay] = k++;
+        }
+        while(ax < n && !a[ax+1][ay]) { // 下方  不过边界 && 未填数
+            a[++ax][ay] = k++;
+        }
+        while(ay > 1 && !a[ax][ay-1]) { // 左侧  不过边界 && 未填数
+            a[ax][--ay] = k++;
+        }
+        while(ax > 1 && !a[ax-1][ay]) { // 上方  不过边界 && 未填数
+            a[--ax][ay] = k++;
+        }
+    }
+
+    for(int i = 1 ; i <= n ; i++) {
+        for(int j = 1 ; j <= n ; j++) {
+            printf("%3d", a[i][j]);
+        }
+        printf("\n");
+    }
+
+    return 0;
+}