976

include/solution/976.h

@@ -0,0 +1,11 @@
+#ifndef INC_976_H
+#define INC_976_H
+#ifdef __cplusplus
+extern "C"
+{
+#endif
+int largestPerimeter(int* nums, int numsSize);
+#ifdef __cplusplus
+}
+#endif
+#endif

src/976.c

@@ -0,0 +1,27 @@
+#include <solution/976.h>
+#include <stdlib.h>
+
+int cmp(const void *a, const void *b)
+{
+    return *(const int *)b - *(const int *)a;
+}
+
+int largestPerimeter(int *nums, int numsSize)
+{
+    qsort(nums, numsSize, sizeof(int), cmp);
+    int i = 0, j = 1;
+
+    while (i < numsSize - 2 && j < numsSize - 1)
+    {
+        int k = j + 1;
+        if (nums[i] < nums[j] + nums[k])
+            return nums[i] + nums[j] + nums[k];
+        else
+        {
+            j++;
+            i++;
+        }
+    }
+
+    return 0;
+}

tests/test_976.cpp

@@ -0,0 +1,65 @@
+#include <gtest/gtest.h>
+#include <solution/976.h>
+// 测试类定义
+class LargestPerimeterTest : public ::testing::Test
+{
+  protected:
+    void AssertLargestPerimeter(std::vector<int> input, int expected)
+    {
+        int *nums = new int[input.size()];
+        std::copy(input.begin(), input.end(), nums);
+
+        int result = largestPerimeter(nums, input.size());
+        ASSERT_EQ(result, expected);
+
+        delete[] nums;
+    }
+};
+
+// 示例 1
+TEST_F(LargestPerimeterTest, Example1)
+{
+    // 输入: nums = [2,1,2]
+    // 输出: 5
+    AssertLargestPerimeter({2, 1, 2}, 5);
+}
+
+// 示例 2
+TEST_F(LargestPerimeterTest, Example2)
+{
+    // 输入: nums = [1,2,1,10]
+    // 输出: 0
+    AssertLargestPerimeter({1, 2, 1, 10}, 0);
+}
+
+// 边界测试：最小输入
+TEST_F(LargestPerimeterTest, SmallestInput)
+{
+    // 输入: nums = [3,4,5]
+    // 输出: 12
+    AssertLargestPerimeter({3, 4, 5}, 12);
+}
+
+// 边界测试：无法组成三角形的情况
+TEST_F(LargestPerimeterTest, CannotFormTriangle)
+{
+    // 输入: nums = [1,1,2]
+    // 输出: 0
+    AssertLargestPerimeter({1, 1, 2}, 0);
+}
+
+// 边界测试：重复元素
+TEST_F(LargestPerimeterTest, RepeatedElements)
+{
+    // 输入: nums = [3,3,3,3,3]
+    // 输出: 9
+    AssertLargestPerimeter({3, 3, 3, 3, 3}, 9);
+}
+
+// 边界测试：无有效三角形
+TEST_F(LargestPerimeterTest, NoValidTriangle)
+{
+    // 输入: nums = [1,1,1,10]
+    // 输出: 3
+    AssertLargestPerimeter({1, 1, 1, 10}, 3);
+}