小米9.19笔试

简单入门题

第一题

给出容量为N的背包、n个物品和c个体积为1的填充块，询问是否能够将背包刚好充满。
价值与体积相同的0/1背包，结尾判断差值是否小于c

#include<bits/stdc++.h>  
using namespace std;  
int main() {  
    int T;  
    cin >> T;  
    while (T--) {  
        int N,n,c;  
        cin >> N >> n >> c;  
        vector<int> nums;  
        for (int i = 0; i < n; i++) {  
            int tmp;  
            cin >> tmp;  
            nums.push_back(tmp);  
        }  
        vector<int> dp(N + 1, 0);  
        //dp[i]容量为i的箱子最多装多少  
        for (int i = 0; i < n; i++) {  
            for (int j = N; j >= nums[i]; j--) {  
                dp[j] = max(dp[j], dp[j - nums[i]] + nums[i]);  
            }  
        }  
        if (N - dp[N] <= c) cout << "YES" << endl;  
        else cout << "NO"<< endl;  
    }  
  
}

第二题

每个位置可以从两个值中选取一个，询问能否组成单调不增或单调不减队列
模拟抽取即可

#include<bits/stdc++.h>  
using namespace std;  
int main() {  
    int T;  
    cin >> T;  
    while (T--) {  
        int n;  
        cin >> n;  
        vector<int> nums1(n);  
        vector<int> nums2(n);  
        for (int i = 0; i < n; i++) {  
            cin >> nums1[i];  
        }  
        for (int i = 0; i < n; i++) {  
            cin >> nums2[i];  
        }  
        //依次考虑升序或者降序  
        int flag = false;  
        int now = 0;  
        for (int i = 0; i < n; i++) {  
            int tmp1 = min(nums1[i], nums2[i]);  
            int tmp2 = max(nums1[i], nums2[i]);  
            if (tmp1 >= now) {  
                now = tmp1;  
            } else if (tmp2 < now) {  
                break;  
            } else now = tmp2;  
            if (i == n - 1) flag = true;  
        }  
        now = 10005;  
        for (int i = 0; i < n; i++) {  
            int tmp1 = min(nums1[i], nums2[i]);  
            int tmp2 = max(nums1[i], nums2[i]);  
            if (tmp2 <= now) {  
                now = tmp2;  
            } else if (tmp1 > now) {  
                break;  
            } else now = tmp1;  
            if (i == n - 1) flag = true;  
        }  
        if (flag) cout <<"YES" << endl;  
        else cout << "NO" << endl;  
  
    }  
    return 0;  
}