1,鸡兔同笼
#include <bits/stdc++.h>
using namespace std;
int main(){
int a,b,ji,tu;
cin >> a >> b;
ji = a;
tu = 0;
while ( ji*2+tu*4!=b ){
ji--;
tu++;
}
cout << ji << " " <<tu;
}
2,调和级数
#include <bits/stdc++.h>
using namespace std;
int main()
{
unsigned long long n,m;
double sum=0;
cin>>m;
for(n=0;sum<m;)
{
n++;
sum=sum+(1.0/n);
if(n>1000000){cout<<"too large";return 0;}
}
cout<<n;
}
3,附上一个简易计算器
#include <bits/stdc++.h>
#define int long long
using namespace std;
signed main(){
unsigned int a,c;
char b;
cin>>a>>b>>c;
if(b=='+')cout<<a<<"+"<<c<<"="<<a+c;
else if(b=='-')cout<<a<<"-"<<c<<"="<<a-c;
else if(b=='*')cout<<a<<"*"<<c<<"="<<a*c;
else if(b=='/')cout<<a<<"/"<<c<<"="<<a/c;
}