Introduction:
Swapping the contents of two variables means exchanging their values. In order to perform this operation, temporary variables are often used. The number of temporary variables required depends on the approach used for swapping.

Approach 1: Using a Single Temporary Variable
One way to swap the contents of two variables is by using a single temporary variable. The steps involved in this approach are as follows:

1. Assign the value of the first variable to the temporary variable.
2. Assign the value of the second variable to the first variable.
3. Assign the value of the temporary variable to the second variable.

Approach 2: Using Two Temporary Variables
Another approach is to use two temporary variables. The steps involved in this approach are as follows:

1. Assign the value of the first variable to the first temporary variable.
2. Assign the value of the second variable to the second temporary variable.
3. Assign the value of the first temporary variable to the second variable.
4. Assign the value of the second temporary variable to the first variable.

Approach 3: Using No Temporary Variables
It is also possible to swap the contents of two variables without using any temporary variables. This can be achieved using arithmetic operations. The steps involved in this approach are as follows:

1. Add the values of both variables and store the sum in the first variable.
2. Subtract the initial value of the second variable from the sum stored in the first variable and store the result in the second variable.
3. Subtract the initial value of the first variable from the sum stored in the second variable and store the result in the first variable.

Conclusion:
In conclusion, the minimum number of temporary variables needed to swap the contents of two variables is 0. This can be achieved by using the approach that does not require any temporary variables. However, if temporary variables are allowed, the minimum number required is 1 using Approach 1.

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