Relation between $24-$hour notation and $12-$hour notation is shown in the following table. Let mm be minutes.

From the above table, we notice the processing of $24-$hour format can be categorized by four categories,

depending on the value of hour. Each category is represented by different color.

In Task A$,$ input time in $24-$hour notation and print out the corresponding $12-$hour notation. There are several

steps.

Name your source code convert$\_24\_$to$\_12.$cpp

Input time in $24-$hour notation to a string variable.

Extract values of hour and minute from input.

$($a$)$ Use find method of string class to find out the index of colon $(,$ a character separating hour and

minute.

$($b$)$ Use substr method of string class to get the substring representing hour and minute.

$($c$)$ Use stoi function to convert a string to the corresponding integers. For example, stoi $("12")$ returns

$12.$

If hour is not in $0,23($that is$,$ hour is smaller than $0$ or hour is larger than $23)$ or minute is not in $[0,59],$

then print "invalid input" and return $-1.$ The word "invalid" cannot be missed.

Depending on the values of hour, print out the corresponding $12-$hour notation.

Here are some sample input$/$output$.$

$($a$)$ When hour or minute is not valid.

in c$++$ with explanation