first

course/7-loops/exercises/1-intro/code.go

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+package main
+
+import (
+	"fmt"
+)
+
+func bulkSend(numMessages int) float64 {
+	// ?
+}
+
+// don't edit below this line
+
+func test(numMessages int) {
+	fmt.Printf("Sending %v messages\n", numMessages)
+	cost := bulkSend(numMessages)
+	fmt.Printf("Bulk send complete! Cost = %.2f\n", cost)
+	fmt.Println("===============================================================")
+}
+
+func main() {
+	test(10)
+	test(20)
+	test(30)
+	test(40)
+	test(50)
+}

course/7-loops/exercises/1-intro/complete.go

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+package main
+
+import (
+	"fmt"
+)
+
+func bulkSend(numMessages int) float64 {
+	totalCost := 0.0
+	for i := 0; i < numMessages; i++ {
+		totalCost += 1 + (float64(i) * 0.01)
+	}
+	return totalCost
+}
+
+// don't edit below this line
+
+func test(numMessages int) {
+	fmt.Printf("Sending %v messages\n", numMessages)
+	cost := bulkSend(numMessages)
+	fmt.Printf("Bulk send complete! Cost = %.2f\n", cost)
+	fmt.Println("===============================================================")
+}
+
+func main() {
+	test(10)
+	test(20)
+	test(30)
+	test(40)
+	test(50)
+}

course/7-loops/exercises/1-intro/expected.txt

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+Sending 10 messages
+Bulk send complete! Cost = 10.45
+===============================================================
+Sending 20 messages
+Bulk send complete! Cost = 21.90
+===============================================================
+Sending 30 messages
+Bulk send complete! Cost = 34.35
+===============================================================
+Sending 40 messages
+Bulk send complete! Cost = 47.80
+===============================================================
+Sending 50 messages
+Bulk send complete! Cost = 62.25
+===============================================================

course/7-loops/exercises/1-intro/readme.md

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+# Loops in Go
+
+The basic loop in Go is written in standard C-like syntax:
+
+```go
+for INITIAL; CONDITION; AFTER{
+  // do something
+}
+```
+
+`INITIAL` is run once at the beginning of the loop and can create
+variables within the scope of the loop.
+
+`CONDITION` is checked before each iteration. If the condition doesn't pass
+then the loop breaks.
+
+`AFTER` is run after each iteration.
+
+For example:
+
+```go
+for i := 0; i < 10; i++ {
+  fmt.Println(i)
+}
+// Prints 0 through 9
+```
+
+## Assignment
+
+At Textio we have a dynamic formula for determining how much a batch of bulk messages costs to send.
+
+### Complete the `bulkSend()` function
+
+This function should return the total cost (as a `float64`) to send a batch of `numMessages` messages. Each message costs `1.0`, plus an additional fee. The fee structure is:
+
+* 1st message: `1.0 + 0.00`
+* 2nd message: `1.0 + 0.01`
+* 3rd message: `1.0 + 0.02`
+* 4th message: `1.0 + 0.03`
+
+Use a loop to calculate the total cost and return it.