深さ優先探索アルゴリズムを実装 部分和問題を解く

main()

function main(arg) {
    const k = 21
    const a = [1,3,7,10,13]

    function dfs(i, sum) {
        if (i === a.length) {
            return sum === k
        }

        if (dfs(i + 1, sum)) {
            return true
        }

        if (dfs(i + 1, sum + a[i])) {
            return true
        }

        return false
    }

    if (dfs(0, 0)) {
        console.log("Yes")
    } else{
        console.log("No")
    }
}

const k = 19
const a = [2,4,6,8,10]

main()

function main(arg) {
    const k = 21
    const a = [1,3,7,10,13]

    function dfs(i, sum) {
        console.log([i, sum])
        if (i === a.length) {
            return sum === k
        }

        if (dfs(i + 1, sum)) {
            console.log(`dfs(${i}, ${sum})`)
            return true
        }

        if (dfs(i + 1, sum + a[i])) {
            console.log(`dfs(${i} + 1, ${sum} + a[i])`)
            return true
        }

        return false
    }

    if (dfs(0, 0)) {
        console.log("Yes")
    } else{
        console.log("No")
    }
}

0,0
1,0
2,0
3,0
4,0
5,0
5,13
4,10
5,10
5,23
3,7
4,7
5,7
5,20
4,17
5,17
5,30
2,3
3,3
4,3
5,3
5,16
4,13
5,13
5,26
3,10
4,10
5,10
5,23
4,20
5,20
5,33
1,1
2,1
3,1
4,1
5,1
5,14
4,11
5,11
5,24
3,8
4,8
5,8
5,21
dfs(4 + 1, 8 + a[i])
dfs(3, 8)
dfs(2 + 1, 1 + a[i])
dfs(1, 1)
dfs(0 + 1, 0 + a[i])
Yes

main()

function main(arg) {
    const k = 21
    const a = [1,3,7,10,13]

    var ans = false

    for (var i = 0; i < 32; i++) {
        //2進数作成
        var bin = i.toString(2)
        for (var j = bin.length; j < a.length; j++) {
            bin += "0"
        }

        bin = bin.split("").map(e => Number(e))

        var sum = 0
        for (var j = 0; j < bin.length; j++) {
            if (bin[j] === 1) {
                sum += a[j]
            }
        }

        if (sum === k) {
            ans = true
            break
        }
    }

    if (ans) {
        console.log("Yes")
    } else {
        console.log("No")
    }
}