impl: q134

solutions/q134/solution.go

@@ -0,0 +1,23 @@
+package q134
+
+func canCompleteCircuit(gas []int, cost []int) int {
+	invalidated := 0
+	start, current, tank := 0, 0, 0
+
+	for {
+		tank = tank + gas[current] - cost[current]
+		current = (current + 1) % len(gas)
+		if tank < 0 {
+			invalidated += (current - start + len(gas)) % len(gas)
+			if invalidated >= len(gas) || current == start {
+				return -1
+			}
+			start = current
+			tank = 0
+		} else if current == start {
+			return start
+		}
+	}
+}
+
+var _ = canCompleteCircuit

solutions/q134/solution_test.go

@@ -0,0 +1,34 @@
+package q134
+
+import (
+	"testing"
+)
+
+func Test_canCompleteCircuit(t *testing.T) {
+	tests := []struct {
+		name string // description of this test case
+		// Named input parameters for target function.
+		gas  []int
+		cost []int
+		want int
+	}{
+		{
+			gas:  []int{1, 2, 3, 4, 5},
+			cost: []int{3, 4, 5, 1, 2},
+			want: 3,
+		},
+		{
+			gas:  []int{2, 3, 4},
+			cost: []int{3, 4, 3},
+			want: -1,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := canCompleteCircuit(tt.gas, tt.cost)
+			if got != tt.want {
+				t.Errorf("canCompleteCircuit() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}