ac_fenwicktree_test.go2

package main

// vim:set ft=go:

import (
	"testing"
)

// vim:set ft=go:

func TestFenwickTree(t *testing.T) {
	N := 5
	ft := NewFenwickTree[int](N)
	tests := []struct {
		title    string
		input    []int
		want     [][]int
		wantsize []int
	}{
		{
			title: "0 2",
			input: []int{0, 2},
			want: [][]int{
				[]int{0, 2, 2, 2, 2, 2},
				[]int{0, 0, 0, 0, 0, 0},
				[]int{0, 0, 0, 0, 0, 0},
				[]int{0, 0, 0, 0, 0, 0},
				[]int{0, 0, 0, 0, 0, 0},
			},
		},
		{
			title: "1 3",
			input: []int{1, 3},
			want: [][]int{
				[]int{0, 2, 5, 5, 5, 5},
				[]int{0, 0, 3, 3, 3, 3},
				[]int{0, 0, 0, 0, 0, 0},
				[]int{0, 0, 0, 0, 0, 0},
				[]int{0, 0, 0, 0, 0, 0},
			},
		},
		{
			title: "2 3",
			input: []int{2, 3},
			want: [][]int{
				[]int{0, 2, 5, 8, 8, 8},
				[]int{0, 0, 3, 6, 6, 6},
				[]int{0, 0, 0, 3, 3, 3},
				[]int{0, 0, 0, 0, 0, 0},
				[]int{0, 0, 0, 0, 0, 0},
			},
		},
	}

	for _, ts := range tests {
		t.Run("FenwickTree.Add:"+ts.title, func(t *testing.T) {
			ft.Add(ts.input[0], ts.input[1])
			for i := 0; i < N; i++ {
				for j := i; j <= N; j++ {
					want := ts.want[i][j]
					got := ft.Sum(i, j)
					if want != got {
						t.Errorf("ft.Sum(%d, %d) after ft.Add(%d, %d) returns wrong value: want=%v got=%v\n", i, j, ts.input[0], ts.input[1], want, got)
					}
				}
			}
		})
	}
}