The problem can be rephrased as follows: “among Foods \(B_1, B_2, \ldots, B_K\), is there a food having the best tastiness of the \(N\) foods (allowing ties)?”

This can be determined as follows, for example.

1. Find the maximum tastiness of the \(N\) foods. (Let this value be \(M\).)
2. For \(j=1,2,\ldots , K\), check if \(A_{B_j}=M\).
3. If there are one or more such \(j\), the answer is Yes; otherwise, the answer is No.

This can be written with for statements and if statements. Beware of the range of indices. Also, be careful not to output Yes multiple times or output No after Yes.

Sample code in C++:

#include <bits/stdc++.h>
using namespace std;

int main(void) {
	int n, k, m;
	int a[100], b[100];

	cin >> n >> k;
	for (int i = 0; i < n; i++)cin >> a[i];
	for (int i = 0; i < k; i++)cin >> b[i];

	m = -1;
	for (int i = 0; i < n; i++)m = max(m, a[i]);

	for (int i = 0; i < k; i++) {
		if (a[b[i] - 1] == m) {
			cout << "Yes" << endl;
			return 0;
		}
	}

	cout << "No" << endl;
	return 0;
}

Sample code in Python:

n,k= map(int, input().split())
a= list(map(int, input().split()))
b= list(map(int, input().split()))

m=max(a)
flag=False

for i in range(k):
	if a[b[i]-1]==m:
		flag=True

if flag:
	print("Yes")
else:
	print("No")