p-value here is P(X>c) when theta is 1, which is 1-c for any c in [0,1].
Let X have a uniform distribution on the interval [0, theta] and suppose we wish to test the hypothesis
Null: Theta is less than or equal to 1
Alternative: Theta is greater than 1
We shall consider test procedures of the form reject the null if X is greater than or equal to c. For each possible value x of X, find the p value if X=x is observed