技術標籤：# L2

思路：計算比自己小的0的個數 大的1的個數

• 利用指標去雙層迴圈
• 下標從1開始處理 因為 stu[i].sum = stu[i-1].zero + stu[i].one 初始化stu[0].zero = 0

#include <iostream>
#include <algorithm>
using namespace std;
const int maxn = 100010;
struct node
{
	int id;
	int yuce;
}data[maxn];
bool cmp(node a, node b)
{
	if(a.id != b.id) return
 
 a.id < b.id;
	else return a.yuce < b.yuce;
}
struct student
{
	int id;
	int zero; //小於
	int one; //大於等於
    int sum;
}stu[maxn];
bool cmp1(student a, student b)
{
	if(a.sum != b.sum) return a.sum > b.sum;
	else return a.id > b.id;
}
int main()
{
	int n;
	cin >> n;
	for(int i = 1; i <=
 
 n; i++)
	{
		cin >> data[i].id >> data[i].yuce;
	}
	sort(data+1, data + n + 1,cmp);
	int k = 1;
	stu[k].id = data[1].id;
	if(data[1].yuce == 1) stu[1].one = 1;
	else stu[1].zero = 1;
	for(int i = 2; i <= n; i++)
	{
		if(data[i].id == stu[k].id)
		{
			if(data[i].yuce == 1)
				stu[k]
 
.one++;
			else stu[k].zero++;
		}
		else
		{
			k++;
			stu[k].id = data[i].id;
			if(data[i].yuce == 1)
				stu[k].one++;
			else
				stu[k].zero++;
		}
	}
	int temp = 0;
	for(int i = 1; i <= k; i++)
	{
		temp += stu[i].zero;
		stu[i].zero = temp;
	}
	temp = 0;
	for(int i = k; i >= 1; i--)
	{
		temp += stu[i].one;
		stu[i].one = temp;
	}
	stu[0].zero = 0;
	for(int i = 1; i <= k; i++)
	{
		stu[i].sum = stu[i-1].zero + stu[i].one;
	}
	sort(stu + 1, stu + k + 1, cmp1);
	cout << stu[1].id;
	return 0;
}

是真的害怕csp