Add: Pairs of Songs With Total Durations Divisible by 60

problems/pairs-of-songs-with-total-durations-divisible-by-60/pairs_of_songs_with_total_durations_divisible_by_60.go

@@ -0,0 +1,10 @@
+package pairs_of_songs_with_total_durations_divisible_by_60
+
+func numPairsDivisibleBy60(time []int) int {
+	ans, m := 0, [60]int{}
+	for _, t := range time {
+		ans += m[(60-t%60)%60]
+		m[t%60]++
+	}
+	return ans
+}

problems/pairs-of-songs-with-total-durations-divisible-by-60/pairs_of_songs_with_total_durations_divisible_by_60_test.go

@@ -0,0 +1,27 @@
+package pairs_of_songs_with_total_durations_divisible_by_60
+
+import "testing"
+
+type caseType struct {
+	input    []int
+	expected int
+}
+
+func TestNumPairsDivisibleBy60(t *testing.T) {
+	tests := [...]caseType{
+		{
+			input:    []int{30, 20, 150, 100, 40},
+			expected: 3,
+		},
+		{
+			input:    []int{60, 60, 60},
+			expected: 3,
+		},
+	}
+	for _, tc := range tests {
+		output := numPairsDivisibleBy60(tc.input)
+		if output != tc.expected {
+			t.Fatalf("input: %v, output: %v, expected: %v", tc.input, output, tc.expected)
+		}
+	}
+}