第 172 场周赛

Posted on | In , | |
Words count in article: 463 | Reading time ≈ 2

5315. 6 和 9 组成的最大数字

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
class Solution {
public:
    string tostr(int n){
        string ret = "";
        while(n){
            ret += n % 10 + '0';
            n /= 10;
        }
        if(ret == "") ret = "0";
        reverse(ret.begin(), ret.end());
        return ret;
    }
    int toint(string n){
        int num = 0;
        for(int i=0; i<n.size(); i++){
            num = num * 10 + n[i]-'0';
        }
        return num;
    }
    int maximum69Number (int num) {
        string rem = tostr(num);
        for(int i=0; i<rem.size(); i++){
            if(rem[i] == '6'){
                rem[i] = '9';
                break;
            }
        }
        return toint(rem);
    }
};

1324. 竖直打印单词

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
class Solution {
public:
    vector<string> printVertically(string s) {
        vector<string> res;
        string tmp = "";
        int maxlen = 0;
        for(int i=0; i<s.size(); i++){
            if(s[i] == ' '){
                res.push_back(tmp);
                maxlen = max(maxlen, (int)tmp.size());
                tmp = "";
                continue;
            }
            tmp += s[i];
        }
        maxlen = max(maxlen, (int)tmp.size());
        res.push_back(tmp);
        vector<string> ret;
        for(int i=0; i<maxlen; i++){
            string cur = "";
            for(int j=0; j<res.size(); j++){
                if(i >= res[j].size()) cur += " ";
                else cur += res[j][i];
            }
            int end = cur.size()-1;
            for(; end>=0; end--){
                if(cur[end] != ' ')
                    break;
            }
            cur = cur.substr(0, end+1);
            ret.push_back(cur);
        }
        return ret;
    }
};

1325. 删除给定值的叶子节点

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
/**
 * Definition for a binary tree node.
 * struct TreeNode {
 *     int val;
 *     TreeNode *left;
 *     TreeNode *right;
 *     TreeNode(int x) : val(x), left(NULL), right(NULL) {}
 * };
 */
class Solution {
public:
    TreeNode* removeLeafNodes(TreeNode* root, int target) {
        if(root == NULL) return NULL;
        if(!root->left && !root->right && root->val == target)
            return NULL;
        if(root->left) root->left = removeLeafNodes(root->left, target);
        if(root->right) root->right = removeLeafNodes(root->right, target);
        if(!root->left && !root->right && root->val == target)
            return NULL;
        else return root;
    }
};

1326. 灌溉花园的最少水龙头数目

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
class Solution {
public:
    int minTaps(int n, vector<int>& ranges) {
        vector<int> lands(n);
        for(int i=0; i<ranges.size(); i++){
            int l = max(0, i-ranges[i]);
            int r = min(n, i+ranges[i]);
            for(int j=l; j<r; j++){
                lands[j] = max(lands[j], r);
            }
        }
        int count = 0;
        int cur = 0;
        while(cur < n){
            if(lands[cur] == 0) return -1;
            cur = lands[cur];
            count++;
        }
        return count;
    }
};
Donate? comment?