Create pdd.md

src/pdd.md

@@ -0,0 +1,109 @@
+```python
+"""第一题"""
+
+mat = [[0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1],
+       [0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1],
+       [0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1],
+       [0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1]]
+
+
+def maxOne(mat):
+    if not mat or len(mat) == 0:
+        return []
+
+    row = len(mat)
+    col = len(mat[0]) if row else 0
+    i, j = -1, -1
+    for idx in range(row):
+        if mat[idx][-1] == 1:
+            i, j = idx, col - 1
+            break
+    if i == -1:
+        return []
+    fin_max = 0
+    while j >= 0 and mat[i][j] == 1:
+        j -= 1
+        fin_max += 1
+    res = [[i+1, fin_max]]
+    tmp_j = j + 1
+    while i + 1 < row:
+        i += 1
+        j = tmp_j
+        if mat[i][j] == 1:
+            cur_max = fin_max - 1
+            while j >= 0 and mat[i][j] == 1:
+                j -= 1
+                cur_max += 1
+            if cur_max > fin_max:
+                res = [[i+1, cur_max]]
+                fin_max = cur_max
+            elif cur_max == fin_max:
+                res.append([i+1, cur_max])
+    return res
+
+print(maxOne(mat))
+
+
+"""第三题"""
+
+class Solution(object):
+    def __init__(self):
+        self.stack = []
+        self.res = 0
+    def dfs(self, arr, x, y, c):
+        m = len(arr)
+        n = len(arr[0]) if m else 0
+        if x - 1 >= 0 and y >= 0 and arr[x-1][y] == 'x':
+            self.stack.append((x-1)*100+y)
+            arr[x-1][y] = '#'
+            self.res += 1
+        if x + 1 < m and y >= 0 and arr[x+1][y] == 'x':
+            self.stack.append((x+1)*100+y)
+            arr[x+1][y] = '#'
+            self.res += 1
+        if x >= 0 and y - 1 >= 0 and arr[x][y-1] == 'x':
+            self.stack.append(x*100+y-1)
+            arr[x][y-1] = '#'
+            self.res += 1
+        if x >= 0 and y + 1 < n and arr[x][y+1] == 'x':
+            self.stack.append(x*100+y+1)
+            arr[x][y+1] = '#'
+            self.res += 1
+        while self.stack:
+            tmp = self.stack.pop()
+            self.dfs(arr, tmp //100, tmp % 100, 'x')
+        return self.res
+
+if __name__ == '__main__':
+    s = Solution()
+    arr = [['x',' ',' ', ' ',' '],['x','x','x',' ','x'],['x','x','x','x','x']]
+    print(s.dfs(arr, 0, 0, 'x'))
+
+
+
+"""第四题"""
+
+
+import heapq
+import sys
+def solution(nums):
+    iters = [iter(l) for l in nums]
+    heap = [(next(it), i) for i, it in enumerate(iters)]
+    heapq.heapify(heap)
+
+    lo, hi = 0, sys.maxsize
+    r = max(heap)[0]
+    while True:
+        l, i = heap[0]
+        if r - l < hi - lo:
+            lo, hi = l, r
+        nxt = next(iters[i], None)
+        if nxt is None:
+            return [lo, hi]
+        r = max(r, nxt)
+        heapq.heappushpop(heap, (nxt, i))
+
+nums = [[1,3,5],[4,8],[2,5]]
+print(solution(nums))
+
+```