[C++知识库]贪心算法习题

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#include<iostream>
#include<algorithm>
using namespace std;
struct Match
{
	int start;
	int end;
}M[1000005];
bool cmp(Match a, Match b)
{
	return a.end < b.end;
}
int main()
{
	int n, i, j,m;
	cin >> n>>m;
	for (i = 0; i < n; i++) cin >> M[i].start >> M[i].end;
	sort(M, M + n, cmp);
	int pos = M[0].end;
	int ans = 1;//第一个区间必须选 
	for (i = 1; i < n; i++)
	{
		if (pos <= M[i].start&& M[i].start <m && M[i].end<m)
		{
			pos = M[i].end;
			ans++;
		}
	}
	cout << ans;
	return 0;
}

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这里没有采用冒泡排序，而是直接采用了C++的sort函数?

#include<iostream>
#include<algorithm>
#define num 1001
using namespace std;
int val[num];//价值
bool cmp(int x, int y) {
	return x > y;
}
int main()
{
	int N, M,sum=0;
	cin >> N >> M;
	for (int i = 1; i <= N; i++)
	{
		cin >> val[i];
	}
	sort(val, val + N,cmp);
	for (int j = 1; j <= M; j++)
	{
		val[j] = 0;
	}
	for (int z = 1; z <= N; z++)
	{
		sum += val[z];
	}
	cout << sum << endl;
	return 0;
}