Data commit

Task/Display-a-linear-combination/Kotlin/display-a-linear-combination.kotlin

@@ -0,0 +1,36 @@
+// version 1.1.2
+
+fun linearCombo(c: IntArray): String {
+    val sb = StringBuilder()
+    for ((i, n) in c.withIndex()) {
+        if (n == 0) continue
+        val op = when {
+            n < 0 && sb.isEmpty() -> "-"
+            n < 0                 -> " - "
+            n > 0 && sb.isEmpty() -> ""
+            else                  -> " + "
+        }
+        val av = Math.abs(n)
+        val coeff = if (av == 1) "" else "$av*"
+        sb.append("$op${coeff}e(${i + 1})")
+    }
+    return if(sb.isEmpty()) "0" else sb.toString()
+}
+
+fun main(args: Array<String>) {
+    val combos = arrayOf(
+        intArrayOf(1, 2, 3),
+        intArrayOf(0, 1, 2, 3),
+        intArrayOf(1, 0, 3, 4),
+        intArrayOf(1, 2, 0),
+        intArrayOf(0, 0, 0),
+        intArrayOf(0),
+        intArrayOf(1, 1, 1),
+        intArrayOf(-1, -1, -1),
+        intArrayOf(-1, -2, 0, -3),
+        intArrayOf(-1)
+    )
+    for (c in combos) {
+        println("${c.contentToString().padEnd(15)}  ->  ${linearCombo(c)}")
+    }
+}