Fix U256SquareRoot hint (lambdaclass#1163)

* clippy fmt

* lint fix

src/hint_processor/cairo_1_hint_processor/hint_processor.rs

@@ -612,29 +612,36 @@ impl Cairo1HintProcessor {
         remainder_high: &CellRef,
         sqrt_mul_2_minus_remainder_ge_u128: &CellRef,
     ) -> Result<(), HintError> {
-        let pow_2_128 = Felt252::from(u128::MAX) + 1u32;
-        let pow_2_64 = Felt252::from(u64::MAX) + 1u32;
-        let value_low = res_operand_get_val(vm, value_low)?;
-        let value_high = res_operand_get_val(vm, value_high)?;
-        let value = value_low + value_high * &pow_2_128;
+        let pow_2_128 = BigUint::from(u128::MAX) + 1u32;
+        let pow_2_64 = BigUint::from(u64::MAX) + 1u32;
+        let value_low = res_operand_get_val(vm, value_low)?.to_biguint();
+        let value_high = res_operand_get_val(vm, value_high)?.to_biguint();
+        let value = value_low + value_high * pow_2_128.clone();
         let sqrt = value.sqrt();
-        let remainder = value - &sqrt * &sqrt;
+        let remainder = value - sqrt.clone() * sqrt.clone();
         let sqrt_mul_2_minus_remainder_ge_u128_val =
-            &sqrt * &Felt252::from(2u32) - &remainder >= pow_2_128;
+            sqrt.clone() * 2u32 - remainder.clone() >= pow_2_128;
 
+        // Guess sqrt limbs.
         let (sqrt1_val, sqrt0_val) = sqrt.div_rem(&pow_2_64);
-        vm.insert_value(cell_ref_to_relocatable(sqrt0, vm)?, sqrt0_val)?;
-        vm.insert_value(cell_ref_to_relocatable(sqrt1, vm)?, sqrt1_val)?;
+        vm.insert_value(
+            cell_ref_to_relocatable(sqrt0, vm)?,
+            Felt252::from(sqrt0_val),
+        )?;
+        vm.insert_value(
+            cell_ref_to_relocatable(sqrt1, vm)?,
+            Felt252::from(sqrt1_val),
+        )?;
 
         let (remainder_high_val, remainder_low_val) = remainder.div_rem(&pow_2_128);
 
         vm.insert_value(
             cell_ref_to_relocatable(remainder_low, vm)?,
-            remainder_low_val,
+            Felt252::from(remainder_low_val),
         )?;
         vm.insert_value(
             cell_ref_to_relocatable(remainder_high, vm)?,
-            remainder_high_val,
+            Felt252::from(remainder_high_val),
         )?;
         vm.insert_value(
             cell_ref_to_relocatable(sqrt_mul_2_minus_remainder_ge_u128, vm)?,

src/tests/cairo_1_run_from_entrypoint_tests.rs

@@ -373,6 +373,14 @@ fn u256_sqrt_zero() {
     );
 }
 
+#[test]
+#[cfg_attr(target_arch = "wasm32", wasm_bindgen_test)]
+fn u256_sqrt_max_num() {
+    let program_data = include_bytes!("../../cairo_programs/cairo-1-contracts/u256_sqrt.casm");
+
+    run_cairo_1_entrypoint(program_data.as_slice(), 257, &[], &[1.into()]);
+}
+
 #[test]
 #[cfg_attr(target_arch = "wasm32", wasm_bindgen_test)]
 fn u256_sqrt_big_num() {