【update】笔试-小米-180920（#12）

D-笔试面经/笔试-小米-180920.md

@@ -2,6 +2,13 @@
 ===
 - 单选 10，多选 10，编程 2
 
+Reference
+---
+- **小米大礼包**：https://blog.csdn.net/amusi1994/article/details/82793376
+- **最优分割**：https://blog.csdn.net/amusi1994/article/details/82793562
+    > [小米算法编程题_笔经面经](https://www.nowcoder.com/discuss/114667?toCommentId=1934155)_牛客网 
+    >> 作者：[阿木寺-CSDN](https://blog.csdn.net/amusi1994)
+
 Index
 ---
 <!-- TOC -->
@@ -25,21 +32,52 @@ int p[210];
 int m;
 
 bool dfs(int i, int sum) {
-    if (i == n + 1) return sum == m;
+    if (i == n) return sum == m;
     if (dfs(i + 1, sum + p[i])) return true;
     if (dfs(i + 1, sum)) return true;
     return false;
 }
 
+int main() {
+
+    scanf("%d", &n);
+    for (int i = 0; i < n; ++i)
+        scanf("%d", &p[i]);
+    scanf("%d", &m);
+
+    if (dfs(0, 0)) 
+        printf("1");
+    else 
+        printf("0");
+
+    return 0;
+}
+```
+
+**加入剪枝**（未测试）
+> [【小米2018-09-20在线笔试】小米大礼包](https://blog.csdn.net/amusi1994/article/details/82793376) - CSDN博客 
+```C++
+#include <stdio.h>
+int n;
+int p[210];
+int m;
+
+bool dfs(int i, int sum) {
+    if (sum > m) return false;  // 剪枝
+    if (i == n) return sum == m;
+    if (dfs(i + 1, sum + p[i])) return true;
+    if (dfs(i + 1, sum)) return true;
+    return false;
+}
 
 int main() {
 
     scanf("%d", &n);
-    for (int i = 1; i <= n; ++i)
+    for (int i = 0; i < n; ++i)
         scanf("%d", &p[i]);
     scanf("%d", &m);
 
-    if (dfs(1, 0)) 
+    if (dfs(0, 0)) 
         printf("1");
     else 
         printf("0");
@@ -48,15 +86,41 @@ int main() {
 }
 ```
 
+
 ## 2. 最优分割
 <div align="center"><img src="../_assets/TIM截图20180920192513.png" height="" /></div>
 
+**思路**
+- 二分查找、动态规划
+- LeetCode [410. 分割数组的最大值](https://leetcode-cn.com/problems/split-array-largest-sum/description/)
+
 **低保**（18%）
 ```python
 n, m = list(map(int, input().split()))
 
 A = list(map(int, input().split()))
 
 if sum(A) % m == 0:
-	print(sum(A) // m)
+    print(sum(A) // m)
+```
+
+**Python**（未测试）
+```python
+# 作者：Tercel818
+# 链接：https://www.nowcoder.com/discuss/114578?type=2&order=0&pos=23&page=1
+# 来源：牛客网
+
+n, m = map(int, input().split())
+nums = list(map(int, input().split()))
+acc_sum = [0]
+for item in nums:
+    acc_sum.append(acc_sum[-1] + item)
+dp = [[float("inf")] * (1 + len(nums)) for _ in range(m + 1)]
+dp[0][0] = 0
+for i in range(1, m + 1):
+    for j in range(1, len(nums) + 1):
+        for k in reversed(range(i - 1, j)):
+            val = max(dp[i - 1][k], acc_sum[j] - acc_sum[k])
+            dp[i][j] = min(val, dp[i][j])
+print(dp[m][len(nums)])
 ```