触宝周赛Week 243

public boolean isSumEqual(String firstWord, String secondWord, String targetWord) {
        int ans = decode(firstWord) + decode(secondWord);
        return ans == decode(targetWord);
}

private int decode(String str) {
        int n = str.length();
        int cnt = 0;
        //从个位开始计算
        for (int i = n - 1, j = 1; i >= 0; i--, j = j * 10) {
            cnt += ((str.charAt(i) - 'a') * j);
        }
        return cnt;
}

public String maxVal(String n, int x) {
        StringBuilder sb = new StringBuilder();
        if (n.charAt(0) == '-') {//若为负数，idx向后移一位
            for (int i = 1; i < n.length(); i++) {
                if (n.charAt(i) - '0' > x) {//负数，大数往后
                    sb.append(n.substring(0, i)).append(x).append(n.substring(i));
                    return sb.toString();
                }
            }
        } else {
            for (int i = 0; i < n.length(); i++) {//正数，大数往前
                if (n.charAt(i) - '0' < x) {
                    sb.append(n.substring(0, i)).append(x).append(n.substring(i));
                    return sb.toString();
                }
            }
        }
        return n + x;
}

public int[] assignTasks(int[] servers, int[] tasks) {
        int n = servers.length , m = tasks.length;
        int[] ans = new int[m];
    
    	//双堆解决
   		//权重从小到大，index从小到大
        PriorityQueue<ServerState> free = new PriorityQueue<>((a , b) -> {
           return a.weight == b.weight ? a.idx - b.idx : a.weight - b.weight;
        });

        for (int i = 0; i < n; i++) {
            free.offer(new ServerState(i , servers[i] , 0));
        }

        PriorityQueue<ServerState> busy = new PriorityQueue<>((a , b) -> {
            return a.ending == b.ending ? (a.weight == b.weight ? a.idx - b.idx : a.weight - b.weight) : a.ending - b.ending;
        });

        for (int i = 0; i < m; i++) {
            ////检测busy中是否有完成时间小于<=当前时间的服务器，若有，则从busy中取出该服务器并加入free中
            while (!busy.isEmpty() && busy.peek().ending <= i){
                free.offer(busy.poll());
            }
            // 如果暂时没有可用的服务器，就用最先完成服务的那个，也就是busy的堆顶
            // 更新服务结束时间，与下标j无关，因为已经不是从j时刻开始了
            if (free.isEmpty()){
                ServerState top = busy.poll();
                top.ending += tasks[i];
                ans[i] = top.idx;
                busy.offer(top);
            }else {
                ServerState cur = free.poll();
                cur.ending = i + tasks[i];
                ans[i] = cur.idx;
                busy.offer(cur);
            }

        }
        return ans;
    }

class ServerState{//存储服务器的info
    int idx;
    int weight;
    int ending;

    public ServerState(int idx , int weight , int ending){
        this.idx = idx;
        this.weight = weight;
        this.ending = ending;
    }
}