排序

一，第一种排序

#include <bits/stdc++.h>

using namespace std;

using ll = long long;

const int N = 2e5 + 10;

vector<int> a;

int b[N];

int main() {

	ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);

	int n;

	cin >> n;

	for (int i = 0; i < n; i++) {

		int x;

		cin >> x;

		a.push_back(x);

	}

	sort(a.begin(), a.end());//库里面自带的快排函数

	a.erase(unique(a.begin(), a.end()), a.end());//去重操作
	//unique()将重复的数字放在后面，然后返回一个迭代器，在重复的数字那里
	//erase消除两个迭代器的位置
	for (auto& x : a) {//遍历
		cout << x << ' ';
	}

}

二，第二种排序

#include <bits/stdc++.h>

using namespace std;

using ll = long long;

const int N = 2e5;
//结构体排序
struct Book {

int high, thick, width;

} b[N];
//cmp即使改变sort排序顺序
bool cmp(const Book &a, const Book &b) {

	if (a.high == b.high && a.thick == b.thick) return a.width > b.width;

	if (a.high == b.high) return a.thick > b.thick;

	return a.high > b.high;

}

int main() {

	ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);

	int n;

	cin >> n;

	for (int i = 1; i <= n; i++) {

		cin >> b[i].high >> b[i].thick >> b[i].width;

	}

	sort(b + 1, b + n + 1, cmp);

	for (int i = 1; i <= n; i++) {

		cout << b[i].high << ' ' << b[i].thick << ' ' << b[i].width << '\n';

	}

}

三，第三种排序

#include <bits/stdc++.h>

using namespace std;

using ll = long long;

const int N = 2e5 + 10;

int a[N];
//桶排序
int main() {

	ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);

	int n;

	cin >> n;

	for (int i = 1; i <= n; i++) {

		int x;

		cin >> x;

		a[x]++;//将值对应的数组中++
	
	}

	for (int i = 0; i <= 2e5; i++) {

		for (int j = 0; j < a[i]; j++) cout << i << ' ';
	
	}

}