哔哩哔哩编程题

最新推荐文章于 2023-11-20 11:09:05 发布

原创最新推荐文章于 2023-11-20 11:09:05 发布 · 252 阅读

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扭蛋机：

#include<iostream>
using namespace std;
int main() {
	int num;
	while (cin >> num) {
		string ret = "";
		while (num != 0) {
			if (num % 2 == 0) {
				num = (num - 2) / 2;
				ret = '3' + ret;
			}
			else {
				num = (num - 1) / 2;
				ret = '2' + ret;
			}
		}
		cout << ret << endl;
	}
	return 0;
}

脸滚键盘：

#include<iostream>
#include<string>
#include<unordered_map>
using namespace std;
int main() {
    int n;
    string S;
    while (getline(cin, S)) {
        int i = 0;
        while (S[i] != ' ') {
            i++;
        }
        string str = S.substr(0, i);
        // 不按照空格输入的字符串，能把字符串按照空格分开的函数
        n = stoi(str);
        string s = S.substr(i+1, S.size());
        unordered_map<char, int> map;
        /*cout << n << endl;
        cout << s << endl;*/
        for (char c : s) {
            map[c]++;
        }
        //for (auto it = map.begin(); it != map.end(); it++) cout << it->first << " : " << it->second << endl;
        int count = 0;
        for (char c : s) {
            if (map[c] == 1) {
                if (count + 1 == n) {
                    cout << "[" << c << "]" << endl;
                    count++;
                    break;
                }
                else {
                    count++;
                }
            }
        }
        if (count < n) cout << "Myon~" << endl; 
    }
    return 0;
}

并查集：

// 查找根节点并进行路径压缩
int find(int x) {
	int t = x;
	// 查找，最后的x就变成了根节点
	while (x != fa[x]) {
		x = fa[x];
	}
	// 路径压缩
	while (t != x) {
		int Tfa = fa[t];
		fa[t] = x;
		t = Tfa;
	}
	return x;
}

// 合并
void merge(int x, int y) {
	int xRoot = find(x);
	int yRoot = find(y);
	if (xRoot != yRoot) {
		fa[xRoot] = yRoot;
	}
}

小A最多会新认识的多少人

并查集的方法

//并查集基本应用，最后别忘了减掉本身
#include<iostream>
#include<algorithm>
#include<stdio.h>
#include<vector>
using namespace std;
vector<int>f;
int find(int x) {
    return x == f[x] ? x : f[x] = find(f[x]);
}
int main(void) {
    int n, ix, m;
    while (cin >> n >> ix >> m) {
        f = vector<int>(n); // 全局向量运行时定义大小
        for (int i = 0; i < n; i++)f[i] = i;
        int ans = 0, b = 0;
        while (m--) {
            int x1, x2;
            // cin >> x1 >> x2;
            // scanf("%d，%d", &x1, &x2);
            scanf_s("%d,%d", &x1, &x2); // vs不支持scanf
            if (x1 == ix || x2 == ix)b++;
            int fx = find(x1), fy = find(x2);
            if (fx != fy)f[fx] = fy;
        }
        for (int i = 0; i < n; i++) {
            if (find(ix) == find(i))ans++;
        }
        cout << ans - b - 1 << endl;
    }
    return 0;
}

图的深度遍历方法

#include<iostream>
#include<vector>

using namespace std;
const int maxn = 1e5 + 8;
vector<int> G[maxn];
int res = 0;

//深度遍历 找到一个集合的人
void dfs(int ai, vector<bool>& v) {
	for (int i = 0; i < G[ai].size(); ++i) {
		if (!v[G[ai][i]]) {
			v[G[ai][i]] = true;
			res++;
			dfs(G[ai][i], v);
		}
	}
	return;
}
int main() {
	int n, ai, m;
	cin >> n >> ai >> m;
	//构建邻接表
	while (m--) {
		int p1, p2;
		char chs;
		cin >> p1 >> chs >> p2;
		G[p1].push_back(p2);
		G[p2].push_back(p1);
	}
	vector<bool> visited(n, false);

	//除去本来就认识的人和自己
	int already = G[ai].size() + 1;
	dfs(ai, visited);

	cout << res - already << endl;
	return 0;
}