add solution for Leetcode 238

leetcode/src/238.c

@@ -0,0 +1,35 @@
+int *productExceptSelf(int *nums, int n, int *returnSize) {
+    int totalProd = 1, prefProd = 1, count0 = 0;
+
+    // Count zeros and calculate product of non-zero elements
+    for (int i = 0; i < n; i++) {
+        if (nums[i] == 0) {
+            count0++;
+        } else {
+            totalProd *= nums[i];
+        }
+    }
+
+    int *res = (int *)malloc(n * sizeof(int));
+
+    for (int i = 0; i < n; i++) {
+        if (nums[i] != 0) {
+            prefProd *= nums[i];
+        }
+        if (count0 > 1) {
+            res[i] = 0;
+        } else {
+            if (count0 == 0) {
+                res[i] = (totalProd / prefProd) * (prefProd / nums[i]);
+            } else {
+                if (nums[i] == 0) {
+                    res[i] = (totalProd / prefProd) * (prefProd);
+                } else {
+                    res[i] = 0;
+                }
+            }
+        }
+    }
+    *returnSize = n;
+    return res;
+}