added my solution for problem Day01

Author: lavaygarg

Problems/Mathematics/Day-01/sol/Lavay Garg/Solution1.cpp

@@ -0,0 +1,24 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+int main() {
+    int t;
+    cin >> t;
+    while (t--) {
+        int a, b, c;
+        cin >> a >> b >> c;
+
+        int diff = abs(a - b);
+        int N = 2 * diff;
+        if (diff == 0 || max({a, b, c}) > N) {
+            cout << -1 << '\n';
+            continue;
+        }
+
+        if (c > N / 2) {
+            cout << c - N / 2 << '\n';
+        } else {
+            cout << c + N / 2 << '\n';
+        }
+    }
+}