AtCoder Beginner Contest 042题解

A - Iroha and Haiku (ABC Edition)

简单模拟即可，判断是否存在两个5一个1。

#include 
using namespace std;
 
int main(){
   
    int A, B, C; cin >> A >> B >> C;
    int five = 0;
    int seven = 0;
    if(A == 5) five++;
    else if(A == 7) seven++;
 
    if(B == 5) five++;
    else if(B == 7) seven++;
 
    if(C == 5) five++;
    else if(C == 7) seven++;
    if(five == 2 && seven == 1) cout << "YES" << endl;
    else cout << "NO" << endl;
    return 0;
}

B - Iroha Loves Strings (ABC Edition)

对字符串排序，然后concatenate即可。排序直接用string库。

#include 
using namespace std;
 
int main(){
   
    vector <string> v;
    int N, L; cin >> N >> L;
    for(int i = 0; i < N; i++){
   
        string s; cin >> s;
        v.emplace_back(s);
    }
    sort(v.begin(), v.end());
    string ans;
    for(auto& s : v){
   
        ans += s;
    }
    cout << ans << endl;
    return 0;
}