Codeforces上通过数超过5W人的题

Codeforces上通过数超过5W人的题

共32题：1000分4题，800分28题。

4A. Watermelon

//判断w能否被分为两个偶数相加
#include<bits/stdc++.h>
using namespace std;
int main(){
  int w;  cin>>w;
  if(w%2==0 && w>2){
    cout<<"YES\n";
  }else{
    cout<<"NO\n";
  }
  return 0;
}

71A. Way Too Long Words

//n个字符串，输出首位字母和长度
#include<bits/stdc++.h>
using namespace std;
int main(){
  int n;  cin>>n;
  for(int i = 1; i <= n; i++){
    string s;  cin>>s;
    if(s.size()>10)cout<<s[0]<<s.size()-2<<s[s.size()-1]<<"\n";
    else cout<<s<<"\n";
  }
  return 0;
}

1A. Theatre Square

//用大小为a*a的石板覆盖m*n的地表，求最少数量
#include<bits/stdc++.h>
using namespace std;
typedef long long LL;//WA at 9
int main(){
  LL n, m, a;
  cin>>n>>m>>a;
  LL x = n%a==0 ? n/a : n/a+1;
  LL y = m%a==0 ? m/a : m/a+1;
  cout<<x*y<<"\n";//1e9*1e9>1e9
  return 0;
}

231A. Team

//3个人，n个问题，输出有几个问题三人中有2人给出了解
#include<bits/stdc++.h>
using namespace std;
int main(){
  int n;  cin>>n;
  int cnt = 0;
  for(int i = 1; i <= n; i++){
    int a, b, c;  cin>>a>>b>>c;
    if(a+b+c>=2)cnt++;
  }
  cout<<cnt<<"\n";
  return 0;
}

158A. Next Round

//n个人的成绩降序，大于等于第k名的进决赛，求多少人进
#include<bits/stdc++.h>
using namespace std;
int main(){
  int n, k;  cin>>n>>k;
  int cnt = 0, kk;
  for(int i = 1; i <= n; i++){
    int x;  cin>>x;
    if(i==k)kk=x;
    if(x<=0)continue;
    
    if(i<=k){
      cnt++;
    }else{
      if(x==kk)cnt++;
      else break;
    }
  }
  cout<<cnt<<"\n";
  return 0;
}

50A. Domino piling

//在n*m的矩阵放置尽可能多2*1的米诺骨牌
#include<bits/stdc++.h>
using namespace std;
int main(){
  int n, m;  cin>>n>>m;
  int x = n/2, y = m/2;
  int cnt = x*y*2;
  if(n%2==1)cnt += m/2;
  if(m%2==1)cnt += n/2;
  cout<<cnt<<"\n";
  return 0;
}

118A. String Task

//输入一个字符串，删掉元音，输出符号.+小写字母
#include<bits/stdc++.h>
using namespace std;
int main(){
  string s;  cin>>s;
  for(int i = 0; i < s.size(); i++){
    s[i] = tolower(s[i]);
    if(s[i]=='a'||s[i]=='o'||s[i]=='y'||s[i]=='e'||s[i]=='u'||s[i]=='i')continue;
    else cout<<"."<<s[i];
  }
  return 0;
}

282A. Bit++

//x初始为0，执行n次--或++的结果
#include<bits/stdc++.h>
using namespace std;
typedef long long LL;
int main(){
  LL x = 0;
  int n; cin>>n;
  for(int i = 0; i < n; i++){
    string s;  cin>>s;
    if(s[0]=='+'||s[2]=='+')x++;
    else x--;
  }
  cout<<x<<"\n";
  return 0;
}

112A. Petya and Strings

//比较两个长度相同的字符串字典序大小，不计大小写
#include<bits/stdc++.h>
using namespace std;
typedef long long LL;
int main(){
  string a, b; cin>>a>>b;
  for(int i = 0; i < a.size(); i++){
    a[i] = tolower(a[i]);
    b[i] = tolower(b[i]);
  }
  if(a==b)cout<<0;
  else if(a<b)cout<<-1;
  else cout<<1;
  return 0;
}

263A. Beautiful Matrix

//一个5*5的矩阵，1个1剩余是0，通过交换相邻把1交换到中间的次数
#include<bits/stdc++.h>
using namespace std;
typedef long long LL;
int main(){
  int dx, dy;
  for(int i = 1; i <= 5; i++){
    for(int j = 1; j <= 5; j++){
      int x;  cin>>x;
      if(x==1){
        dx = i, dy = j;
      }
    }
  }
  cout<<abs(3-dx)+abs(3-dy);
  return 0;
}

339A. Helpful Maths

//给出一个竖式字符串，重新排序。
#include<bits/stdc++.h>
using namespace std;
typedef long long LL;
int main(){
  string s;  cin>>s;
  sort(s.begin(), s.end());
  for(int i = 0; i < s.size(); i++){
    if(s[i]=='+')continue;
    cout<<s[i];
    if(i!=s.size()-1)cout<<"+";
  }
  return 0;
}

281A. Word Capitalization

//给出一个字符串，大写第一个字母
#include<bits/stdc++.h>
using namespace std;
typedef long long LL;
int main(){
  string s;  cin>>s;
  s[0] = toupper(s[0]);
  cout<<s;
  return 0;
}

266A. Stones on the Table

//给出一个RGB字符串，取走n个，使相邻的不同
#include<bits/stdc++.h>
using namespace std;
typedef long long LL;
int main(){
  int n;  cin>>n;
  string s;  cin>>s;
  int cnt = 0, l = 0;
  for(int i = 1; i < s.size(); i++){
    if(s[i]==s[l]){
      cnt++;
      continue;
    }else{
      l = i;
    }
  }
  cout<<cnt<<"\n";
  return 0;
}

236A. Boy or Girl

//给出一个字符串，判断不同字符数量个数
#include<bits/stdc++.h>
using namespace std;
typedef long long LL;
int main(){
  string s;  cin>>s;
  set<char>se;
  for(int i = 0; i < s.size(); i++){
    se.insert(s[i]);
  }
  if(se.size()%2==0)cout<<"CHAT WITH HER!";
  else cout<<"IGNORE HIM!";
  return 0;
}

96A. Football

//给出一个字符串，判断有没有7个连续的0或1
#include<bits/stdc++.h>
using namespace std;
typedef long long LL;
int main(){
  string s;  cin>>s;
  int ok = 0, cnt = 1;
  for(int i = 1; i < s.size(); i++){
     if(s[i]==s[i-1])cnt++;
     else{
       if(cnt>=7)ok = 1;
       cnt = 1;
     }
  }
  if(cnt>=7)ok = 1;//wa at 4
  if(ok==1)cout<<"YES\n";
  else cout<<"NO";
  return 0;
}

69A. Young Physicist

//给出n个3维坐标，判断其矢量和是否为0，直接累加。
#include<bits/stdc++.h>
using namespace std;
typedef long long LL;
int main(){
  int n, a=0, b=0, c=0;
  cin>>n;
  for(int i = 0; i < n; i++){
    int x, y, z;  cin>>x>>y>>z;
    a += x; b += y;  c += z;
  }
  if(a==0 && b==0 && c==0){
    cout<<"YES\n";
  }else{
    cout<<"NO";
  }
  return 0;
}

546A. Soldier and Bananas

//费用为s=k+2k+3k+..wk，求n和s的差值
#include<bits/stdc++.h>
using namespace std;
typedef long long LL;
int main(){
  LL n, k, w; cin>>k>>n>>w;
  LL s = 0;
  for(int i = 1; i <= w; i++){
    s += i*k;
  }
  if(s>n)cout<<s-n;
  else cout<<0;
  return 0;
}

791A. Bear and Big Brother

//体重a和b，每年a=3a,b=2b，求什么时候a>b
#include<bits/stdc++.h>
using namespace std;
typedef long long LL;
int main(){
  LL a, b;
  cin>>a>>b;
  int cnt = 0;
  while(a<=b){
    cnt++;
    a *= 3;
    b *= 2;
  }
  cout<<cnt<<"\n";
  return 0;
}

977A. Wrong Subtraction

//将一个整数n减k次，末位非零减一，为零就去掉。
#include<bits/stdc++.h>
using namespace std;
typedef long long LL;
int main(){
  int n, k; cin>>n>>k;
  for(int i = 0; i < k; i++){
    if(n%10!=0)n--;
    else {
      n = n/10;
    }
  }
  cout<<n<<"\n";
  return 0;
}

116A. Tram

//电车停n次，下来ai个上来bi个，求最小可行容量
#include<bits/stdc++.h>
using namespace std;
typedef long long LL;
int main(){
  int n;  cin>>n;
  int mi = 0, pe = 0;
  for(int i = 0; i < n; i++){
    int a, b;  cin>>a>>b;
    pe -= a;  pe += b;
    mi = max(mi, pe);
  }
  cout<<mi<<"\n";
  return 0;
}

58A. Chat room

//给出一个字符串，判断是否包含hello
#include<bits/stdc++.h>
using namespace std;
typedef long long LL;
int main(){
  string s;  cin>>s;
  string t = "hello"; int cur =0;
  for(int i = 0; i < s.size(); i++){
    if(s[i]==t[cur])cur++;
  }
  if(cur>=5)cout<<"YES\n";
  else cout<<"NO\n";
  return 0;
}

617A. Elephant

//从原点出发，每次1-5步，最少几次恰好到x
//当前f[x],从f[i-1]~f[i-5]转移而来，每次取最小的+1
#include<bits/stdc++.h>
using namespace std;
typedef long long LL;
int f[1000010];
int main(){
  int x;  cin>>x;
  f[1] = f[2] = f[3] = f[4] = f[5] = 1;
  for(int i = 6; i <= x; i++){
    f[i] = 1e9;
    f[i] = min(f[i],f[i-1]);
    f[i] = min(f[i],f[i-2]);
    f[i] = min(f[i],f[i-3]);
    f[i] = min(f[i],f[i-4]);
    f[i] = min(f[i],f[i-5]);
    f[i]++;
  }
  cout<<f[x]<<"\n";
  return 0;
}

122A. Lucky Division

//判断一个数字是否仅由47构成或者可以被47构成的数字整除.
#include<bits/stdc++.h>
using namespace std;
typedef long long LL;
int di[]={4,7,44,77,47,444,777,447,474,744,774,747,477};
int main(){
  int x;  cin>>x;
  int ok = 0;
  for(int i = 0; i < 13; i++){
    if(x==di[i]||x%di[i]==0){
      ok = 1;
    }
  }
  if(ok==1)cout<<"YES\n";
  else cout<<"NO\n";
  return 0;
}

59A. Word

//给出一个字符串，修改尽可能少的字符使其全大写或全小写
#include<bits/stdc++.h>
using namespace std;
typedef long long LL;
int main(){
  string s;  cin>>s;
  int low = 0;
  for(int i = 0; i < s.size(); i++){
    if(islower(s[i]))low++;
  }
  if(low>=s.size()-low){
    for(int i = 0; i < s.size(); i++){
      s[i] = tolower(s[i]);
    }
    cout<<s;
  }else{
    for(int i = 0; i < s.size(); i++){
      s[i] = toupper(s[i]);
    }
    cout<<s;
  }
  return 0;
}

266B. Queue at the School

//给出一个GB字符串，每秒扫一遍，把BG换成GB
#include<bits/stdc++.h>
using namespace std;
typedef long long LL;
int main(){
  int n, t;  cin>>n>>t;
  string s;  cin>>s;
  for(int i = 0; i < t; i++){
    int cur = 0;
    while(s.find("BG",cur)!=string::npos){
      cur = s.find("BG",cur);
      s[cur] = 'G';
      s[cur+1] = 'B';
      cur = cur+2;
      //cout<<cur<<" "<<s<<"\n";
    }
  }
  cout<<s<<"\n";
  return 0;
}

160A. Twins

//n枚硬币，从中选出最少个数使其总价值大于总和的一半
#include<bits/stdc++.h>
using namespace std;
typedef long long LL;
int a[110];
int main(){
  int n;  cin>>n;
  int sum = 0;
  for(int i = 1; i <= n; i++){
    cin>>a[i];  sum+=a[i];
  }
  sort(a+1,a+n+1);
  int now = 0, cnt = 0;
  for(int i = n; i >= 1; i--){
    if(2*now>sum){
      break;
    }else{
      now += a[i];
      cnt++;
    }
  }
  cout<<cnt<<"\n";
  return 0;
}

110A. Nearly Lucky Number

//判断一个数字中4和7的个数，是否只由4和7构成.
#include<bits/stdc++.h>
using namespace std;
typedef long long LL;
int main(){
  string s;  cin>>s;
  int cnt = 0;
  for(int i = 0; i < s.size(); i++){
    if(s[i]=='4'||s[i]=='7')cnt++;
  }
  
  if(cnt==0){
    cout<<"NO\n"; return 0;
  }
  int ok = 1;
  while(cnt){
    if(cnt%10==4||cnt%10==7){
      cnt /= 10; continue;
    }else{
      ok = 0; break;
    }
  }
  
  if(ok==1)cout<<"YES\n";
  else cout<<"NO\n";
  return 0;
}

41A. Translation

//判断字符串t是否是s的取反
#include<bits/stdc++.h>
using namespace std;
typedef long long LL;
int main(){
  string s, t;  cin>>s>>t;
  reverse(s.begin(),s.end());
  
  if(s==t)cout<<"YES\n";
  else cout<<"NO\n";
  return 0;
}

734A. Anton and Danik

//输入一个AD字符串， 统计A和D谁多
#include<bits/stdc++.h>
using namespace std;
typedef long long LL;
int main(){
  int n;  cin>>n;
  string s;  cin>>s;
  int a = 0, d = 0;
  for(int i = 0; i < s.size(); i++){
    if(s[i]=='A')a++;
    else d++;
  }
  
  if(a==d)cout<<"Friendship\n";
  else if(a>d)cout<<"Anton\n";
  else cout<<"Danik";
  return 0;
}

133A. HQ9+

//判断一个字符串是否包含HQ9+
#include<bits/stdc++.h>
using namespace std;
typedef long long LL;
int main(){
  int ok = 0;
  string s;  cin>>s;
  for(int i = 0; i < s.size(); i++){
    if(s[i]=='H'||s[i]=='Q'||s[i]=='9')ok = 1;
  }
  if(ok==1)cout<<"YES\n";
  else cout<<"NO\n";
  return 0;
}

271A. Beautiful Year

//找出比给定年份大的第一个四位数字都不同的年份
#include<bits/stdc++.h>
using namespace std;
typedef long long LL;
int main(){
  int n;  cin>>n;  n++;
  while(1){
    int g=n%10, s=n/10%10, b = n/100%10, q = n/1000;
    int z[15] = {0};
    z[g] = z[s] = z[b] = z[q] = 1;
    int cnt = 0;
    for(int i = 0; i <= 9; i++)
      if(z[i]==1)cnt++;
    if(cnt==4){
      cout<<n;
      return 0;
    }
    n++;
  }
  return 0;
}

467A. George and Accommodation

//n个房间的人数和大小，求能住两个人的房间个数
#include<bits/stdc++.h>
using namespace std;
typedef long long LL;
int main(){
  int n;  cin>>n;
  int cnt = 0;
  for(int i = 0; i < n; i++){
    int a, b;  cin>>a>>b;
    if(b-a>=2)cnt++;
  }
  cout<<cnt<<"\n";
  return 0;
}