ex1

var grades:[String:Int] = ["Eran":100,"Eli":95,"Shlomi":15,"Nissim":30,"Ohad":93,"Moshe":96,"Danny":85,"Yaron":78]

var bottomGrade : Int = 100
var topGrade : Int = 0
var sum : Int = 0
var topName : String = ""
var bottomName : String = ""
var i = 0
var j = 0
var topList:[String] = []
var bottomList:[String] = []
for student in grades {
    sum += student.value
    if student.value > 95 {
        topList.append(student.key)
    }
    if student.value < 55 {
        bottomList.append(student.key)
    }
    if student.value > topGrade {
        topGrade = student.value
        topName = student.key
    }
    if student.value < bottomGrade {
        bottomGrade = student.value
        bottomName = student.key
    }
}

print("\(topName) has the highest grade - \(topGrade)")
print("\(bottomName) has the lowest grade - \(bottomGrade)")
print("Failed students names:")
for s in bottomList {
    if grades.keys.contains(s) {
        print(s)
    }
}
print("Best students names:")
for s in topList {
    if grades.keys.contains(s) {
        print(s)
    }
}
print("average - \(sum/grades.count)")