メニューjavascriptの更新

function combination(arr, n) {
    const result = [];
    if (n === 1) return arr.map(e => [e]);
    
    arr.forEach((e,i,arr) => {
        const copy = arr.slice(i+1);
        const cases = combination(copy, n-1);
        const combi = cases.map(v => [e, ...v]);
        result.push(...combi);
    })
    
    return result;
}

function solution(orders, course) {
    const answer = [];
    
    course.forEach(num => {
        const map = new Map();
        
        orders.forEach(menu => {
            const menuArr = menu.split('').sort();
            const combinations = combination(menuArr, num);
            
            combinations.forEach(e => {
                const key = e.join('');
                map.set(key, map.get(key) + 1 || 1);
            })
        })
        
        const setMenu = [...map].sort((a,b) => b[1] - a[1]);
        
        for (let i = 0; i < setMenu.length; i++) {
            const max = setMenu[0][1];
            
            if (max === 1) break;
            if (setMenu[i][1] < max) break;
            
            answer.push(setMenu[i][0]);
        }
    })
    
    return answer.sort();
}

combinations.forEach(e => {
                const key = e.join('');
                map.set(key, map.get(key) + 1 || 1);
            })
/* map: 	[
  [ 'AB', 1 ], [ 'AC', 4 ],
  [ 'AF', 1 ], [ 'AG', 1 ],
  [ 'BC', 2 ], [ 'BF', 2 ],
  [ 'BG', 2 ], [ 'CF', 2 ],
  [ 'CG', 2 ], [ 'FG', 2 ],
  [ 'CD', 3 ], [ 'CE', 3 ],
  [ 'DE', 3 ], [ 'AD', 2 ],
  [ 'AE', 2 ], [ 'AH', 1 ],
  [ 'CH', 1 ], [ 'DH', 1 ],
  [ 'EH', 1 ]
] */