CODE FESTIVAL 2017 qual B B

CODE FESTIVAL 2017 qual B B - Problem Set

确实水题，但当时没想到map，用sort后逐个比较解决的，感觉麻烦些，虽然效率高很多。map确实好写点。

用map：

 1 #include<iostream>
 2 #include<cstdio>
 3 #include<cstdlib>
 4 #include<map>
 5 using namespace std;
 6 map<int,int>mp;
 7 
 8 int main()
 9 {
10     int n,m,x;
11     cin>>n;
12     for(int i=0;i<n;i++){
13         cin>>x;
14         mp[x]++;
15     }
16     cin>>m;
17     for(int i=0;i<m;i++){
18         cin>>x;
19         if(mp[x]==0){
20             cout<<"NO"<<endl;
21             exit(0);
22         }else mp[x]--;
23     }
24     cout<<"YES"<<endl;
25     return 0;
26 }

直接sort

 1 #include<cstdio>
 2 #include<algorithm>
 3 using namespace std;
 4 const int maxn = 200500;
 5 int d[maxn], t[maxn];
 6  
 7 int main()
 8 {
 9     int N, M;
10     scanf("%d", &N);
11     for (int i = 1; i <= N; i++) scanf("%d", &d[i]);
12     scanf("%d", &M);
13     for (int i = 1; i <= M; i++) scanf("%d", &t[i]);
14     sort(d+1, 1 + N+d);
15     sort(t+1, 1 + M+t);
16     int p1 = 1, p2 = 1;
17     bool flag = false;
18     while (p1<=M&&p2<=N)
19     {
20         if (p1 != M) {
21             if (d[p2] == t[p1]) {
22                 p2++, p1++;
23             }
24             else {
25                 p2++;
26             }
27         }
28         else
29         {
30             if (d[p2] == t[p1]) {
31                 flag = true;
32                 break;
33             }
34             else
35             {
36                 p2++;
37             }
38         }
39     }
40     if (flag) printf("YES
");
41     else printf("NO
");
42     return 0;
43 }