markdown AtCoder初学者比赛089

Posted 2021-05-06

#include <iostream>
#include <stdio.h>
#include <string>
#include <vector>

using namespace std;

int main(){
  unsigned long long N = 0;
  unsigned long long M=0, A=0, R=0, C=0, H=0;
  cin >> N;
  string s;
  for(int i=0; i<N; i++){
    cin >> s;
    if(s[0]=='M'){
      M+=1;
    }else if(s[0]=='A'){
      A+=1;
    }else if(s[0]=='R'){
      R+=1;
    }else if(s[0]=='C'){
      C+=1;
    }else if(s[0]=='H'){
      H+=1;
    }
  }
  unsigned long long sum = 0;
  sum += M * A * R;
  sum += M * A * C;
  sum += M * A * H;
  sum += M * R * C;
  sum += M * R * H;
  sum += M * C * H;
  sum += A * R * C;
  sum += A * R * H;
  sum += A * C * H;
  sum += R * C * H;
  printf("%llu\n", sum);
  return 0;
}

#include <iostream>
#include <stdio.h>
#include <string>
#include <set>

using namespace std;

int main(){
  int N = 0;
  set<string> st;
  cin >> N;
  string s;
  for(int i=0; i<N; i++){
    cin >> s;
    st.insert(s);
  }

  if(int(st.size())==3){
    printf("Three\n");
  }else if(int(st.size())==4){
    printf("Four\n");
  }
  return 0;
}

#include <iostream>
#include <stdio.h>

using namespace std;

int main(){
  int N = 0;
  cin >> N;
  printf("%d\n", int(N/3));
}

https://beta.atcoder.jp/contests/abc089/tasks