diff --git a/sorting1.c b/sorting1.c
new file mode 100644
index 0000000..cedb0bf
--- /dev/null
+++ b/sorting1.c
@@ -0,0 +1,39 @@
+#include <stdio.h>
+
+// Function to calculate trapped rain water
+int trap(int* height, int heightSize) {
+    if (heightSize == 0) return 0;
+
+    int left = 0, right = heightSize - 1;
+    int leftMax = 0, rightMax = 0;
+    int water = 0;
+
+    while (left < right) {
+        if (height[left] < height[right]) {
+            if (height[left] >= leftMax) {
+                leftMax = height[left];
+            } else {
+                water += leftMax - height[left];
+            }
+            left++;
+        } else {
+            if (height[right] >= rightMax) {
+                rightMax = height[right];
+            } else {
+                water += rightMax - height[right];
+            }
+            right--;
+        }
+    }
+    return water;
+}
+
+int main() {
+    int height[] = {4, 2, 0, 3, 2, 5};
+    int heightSize = sizeof(height) / sizeof(height[0]);
+
+    int result = trap(height, heightSize);
+    printf("Trapped rain water: %d\n", result);
+
+    return 0;
+}