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src/s0704_binary_search.cpp

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+#include "s0704_binary_search.hpp"
+
+// 闭区间写法
+int Solution1::binSearch(vector<int>& nums, int target) {
+  int len = nums.size();
+  int l{0};
+  int r = len - 1;
+  while (l <= r) {
+    int m = (l + r) >> 1;
+    if (target < nums[m]) {
+      r = m - 1;
+    } else if (nums[m] < target) {
+      l = m + 1;
+    } else {
+      return m;
+    }
+  }
+  return -1;
+}
+
+// 开区间写法
+int Solution2::binSearch(vector<int>& nums, int target) {
+  int len = nums.size();
+  int l{0};
+  int r = len;
+  while (l < r) {
+    int m = (l + r) >> 1;
+    if (target < nums[m]) {
+      r = m;
+    } else if (nums[m] < target) {
+      l = m + 1;
+    } else {
+      return m;
+    }
+  }
+  return -1;
+}