2019 蓝桥杯省赛 B 组模拟赛 程序设计：快速过河

题目：



代码如下：

#include
using namespace std;
#define MAX 1005
int a[MAX],dp[MAX];
int main()
{
	int n;
	cin >> n;
	for(int i = 0;i < n;i++) cin >> a[i];
	sort(a,a + n);
	dp[0] = a[0];
	dp[1] = a[1];
	for(int i = 2;i < n;i++) dp[i] = min(dp[i - 1] + a[i] + a[0],dp[i - 2] + a[0] + 2 * a[1] + a[i]);
	cout << dp[n - 1] << endl;
	n--;
	while(1){
		if(n == 0){
			cout << 1 << " " << a[0] << endl;
			break;
		}
		else if(n == 1){
			cout << 2 << " " << a[0] << " " << a[1] << endl;
			break;
		}
		else if(n == 2){
			cout << 2 << " " << a[0] << " " << a[1] << endl;
			cout << 1 << " " << a[0] << endl;
			cout << 2 << " " << a[0] << " " << a[2] << endl;
			break;
		}
		else{
			if(a[0] * 2 + a[n - 1] + a[n] > a[0] + 2 * a[1] + a[n]){
				cout << 2 << " " << a[0] << " " << a[1] << endl;
				cout << 1 << " " << a[0] << endl;
				cout << 2 << " " << a[n - 1] << " " << a[n] << endl;
				cout << 1 << " " << a[1] << endl;
				n -= 2;
				break;
			}
			else{
				cout << 2 << " " << a[0] << " " << a[n] << endl;
				cout << 1 << " " << a[0] << endl;
				n--;
				break;
			}
		}
	}
	return 0;
}

这道题的dp在之前的博客已经讲过，主要是如何保存来的过程，这里采用贪心的方法去完成。
具体如下：