1. The evaluation method is linear. If n is the length of the input expression, then the main loop cannot execute more than n times (since each iteration of the loop reads and processes at least one...

1. The evaluation method is linear. If
n
is the length of the input expression, then the main loop cannot execute more than
n
times (since each iteration of the loop reads and processes at least one character). Moreover, each iteration performs no more than a constant number of operations, so
n
iterations will do no more than a constant times
n
operations.