feat: add lerp (TheAlgorithms#545)

* add lerp

* fix: add description

math/lerp.go

@@ -0,0 +1,8 @@
+package math
+
+// Lerp or Linear interpolation
+// This function will return new value in 't' percentage  between 'v0' and 'v1'
+func Lerp(v0, v1, t float64) float64 {
+	// see: https://en.wikipedia.org/wiki/Linear_interpolation
+	return (1-t)*v0 + t*v1
+}

math/lerp_test.go

@@ -0,0 +1,29 @@
+package math_test
+
+import (
+	"testing"
+
+	algmath "github.com/TheAlgorithms/Go/math"
+)
+
+func TestLerp(t *testing.T) {
+	tests := []struct {
+		name       string
+		testValues []float64
+		answer     float64
+	}{
+		{"Lerp(1,1,1)", []float64{1, 1, 1}, 1},
+		{"Lerp(0,1,1)", []float64{0, 1, 1}, 1},
+		{"Lerp(0,1,0.5)", []float64{0, 1, 0.5}, 0.5},
+		{"Lerp(0,1,0.1)", []float64{0, 1, 0.1}, 0.1},
+	}
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			got := algmath.Lerp(test.testValues[0], test.testValues[1], test.testValues[2])
+			if got != test.answer {
+				t.Errorf("Lerp(%f,%f,%f) = %v, want %v", got, test.testValues[0],
+					test.testValues[1], test.testValues[2], test.answer)
+			}
+		})
+	}
+}