【leetcode】LCP 66. Minimum number of booths (implemented by js)

1. Topic

LCP 66. Minimum number of booths

2. Idea

1. First count the number of booths needed each day;
2. Then select the maximum number of booths of each type;
3. Finally, add the maximum number of each booth and return.

• Taking test case 1 as an example, it will be easier to understand with this picture.
  

3. Code implementation

/**
 * @param {string[]} demand
 * @return {number}
 */
var minNumBooths = function(demand) {
    
    
    // 索引为字母在字母表中的位置，值为出现的个数
    let arr = new Array(26).fill(0) 
    for (let str of demand) {
    
    
        let map = new Map()
        for (let i = 0; i < str.length; i++) {
    
    
            let key = str.charCodeAt(i) - 97
            map.set(key, (map.get(key) || 0) + 1)
        }
        for (let [key, val] of map) {
    
    
            arr[key] = Math.max(val, arr[key])
        }
    }
    let cnt = 0
    arr.forEach(item => cnt += item)
    return cnt
};

4. Reference

[Han Ergou] Go/Java/JavaScript Hash + Analog Double Hundred