【Level.1】CTOからの挑戦状2016 2nd～GistURL回答～

q1.js

// 手続き
function selectOptimumCombination(amount, myCoupons) {
    var selectedCoupons = [0, 0, 0];

    if(amount>1000){

        while(myCoupons[0]>0){
            if(amount<500) break;
            amount=amount-500;
            myCoupons[0]--;
            selectedCoupons[0]++;
        }

        while(myCoupons[1]>0){
            if(amount<200) break;
                amount=amount-200;
                myCoupons[1]--;
                selectedCoupons[1]++;
        }

        while(myCoupons[2]>0){
            if(amount<100) break;
                amount=amount-100;
                myCoupons[2]--;
                selectedCoupons[2]++;
        }
    }
    return selectedCoupons;
}

// ケース3
console.log(selectOptimumCombination(1210, [2, 1, 3]));