2020 年百度之星·程序设计大赛 - 初赛一

题目链接：http://bestcoder.hdu.edu.cn/contests/contest_show.php?cid=889
题解链接：http://bestcoder.hdu.edu.cn/

1001 Drink

一道比较水的模拟

#include 
using namespace std;

int main(void)
{
	int t, n, m, x, y;
	int res, num, k;
	scanf("%d", &t);
	while (t--) {
		res = 0x3f3f3f3f;
		scanf("%d%d", &n, &m);
		for (int i = 0; i < n; i++) {
			scanf("%d%d", &x, &y);
			num = m / x;
			if (m != num * x)
				num++;
			k = num * y;
			res = min(res, k);
		}
		printf("%d\n", res);
	}
	
	return 0;
}

1002 GPA

dp，和01背包有些相似

#include 
using namespace std;

int sco[] = {95, 90, 85, 80, 75, 70, 67, 65, 62, 60, 0};
double gpa[] = {4.3, 4.0, 3.7, 3.3, 3.0, 2.7, 2.3, 2.0, 1.7, 1.0, 0};

double dp[5][405];

int main(void)
{
	int t, x, cnt;
	for (int i = 0; i < 4; i++)
		for (int j = 0; j <= 400; j++)
			for (int k = 0; k < 11; k++)
				if (j >= sco[k])
					dp[i + 1][j] = max(dp[i + 1][j], dp[i][j - sco[k]] + gpa[k]); 
	
	scanf("%d", &t);
	while (t--) {
		scanf("%d", &x);
		printf("%.1lf\n", dp[4][x]);
	}
	
	return 0;
}

1003 Dec

dp，跟走网格的题有些类似

#include 
using namespace std;
const int N = 1005;

int dp[N][N];

int gcd(int a, int b)
{
	if (b == 0) return a;
	return gcd(b, a % b);
}

int main(void)
{
	int t, a, b;
	for (int i = 1; i <= 1000; i++) {
		dp[i][1] = dp[1][i] = i;
	}
	int flag;
	for (int i = 2; i <= 1000; i++) {
		for (int j = 2; j <= 1000; j++) {
			flag = (gcd(i, j) == 1 ? 1 : 0);
			dp[i][j] = max(dp[i - 1][j], dp[i][j - 1]) + flag;
		}
	}
	scanf("%d", &t);
	while (t--) {
		scanf("%d%d", &a, &b);
		printf("%d\n", dp[a][b]);
	}
	
	return 0;
}