add: loop for statement exercises

13-loops/exercises/07-multiplication-table-exercises/01-dynamic-table/main.go

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+// For more tutorials: https://blog.learngoprogramming.com
+//
+// Copyright © 2018 Inanc Gumus
+// Learn Go Programming Course
+// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
+//
+
+package main
+
+// ---------------------------------------------------------
+// EXERCISE: Dynamic Table
+//
+//  Get the size of the table from the command-line
+//    Passing 5 should create a 5x5 table
+//    Passing 10 for a 10x10 tableCreate an infinite loop
+//
+// RESTRICTION
+//  Solve this exercise without looking at the original
+//  multiplication table exercise.
+//
+// HINT
+//  There was a max constant in the original program.
+//  That determines the size of the table.
+//
+// EXPECTED OUTPUT
+//
+//  go run main.go
+//    Give me the size of the table
+//
+//  go run main.go -5
+//    Wrong size
+//
+//  go run main.go ABC
+//    Wrong size
+//
+//  go run main.go 1
+//    X    0    1
+//    0    0    0
+//    1    0    1
+//
+//  go run main.go 2
+//    X    0    1    2
+//    0    0    0    0
+//    1    0    1    2
+//    2    0    2    4
+//
+//  go run main.go 3
+//    X    0    1    2    3
+//    0    0    0    0    0
+//    1    0    1    2    3
+//    2    0    2    4    6
+//    3    0    3    6    9
+// ---------------------------------------------------------
+
+func main() {
+}

13-loops/exercises/07-multiplication-table-exercises/01-dynamic-table/solution/main.go

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+// For more tutorials: https://blog.learngoprogramming.com
+//
+// Copyright © 2018 Inanc Gumus
+// Learn Go Programming Course
+// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
+//
+
+package main
+
+import (
+	"fmt"
+	"os"
+	"strconv"
+)
+
+func main() {
+	args := os.Args
+
+	if len(args) != 2 {
+		fmt.Println("Give me the size of the table")
+		return
+	}
+
+	size, err := strconv.Atoi(args[1])
+	if err != nil || size <= 0 {
+		fmt.Println("Wrong size")
+		return
+	}
+
+	// print the header
+	fmt.Printf("%5s", "X")
+	for i := 0; i <= size; i++ {
+		fmt.Printf("%5d", i)
+	}
+	fmt.Println()
+
+	for i := 0; i <= size; i++ {
+		// print the vertical header
+		fmt.Printf("%5d", i)
+
+		// print the cells
+		for j := 0; j <= size; j++ {
+			fmt.Printf("%5d", i*j)
+		}
+		fmt.Println()
+	}
+}