Cantor的数表,注意一些题中数学的应用

本题主要注意平时做题的时候注意使用数学简化时间复杂度，

贴上自己敲的不用解方程求n得代码：

#include<cstdio>#include<cmath>#include<iostream>#include<algorithm>#include<cstring>#include<string>#include<cctype>#include<cassert>#include<cmath>#include<algorithm>#include<cctype>#include<map>#include<vector>#include<stack>#include<queue>#include<set>#include<cstdlib>using namespace std;int main(){    int n;    while(cin>>n)    {        int i;        for(i=1;i<=10000;i++)            if(i*(i+1)/2>=n)            break;        int a,b;        if(i%2==0)        {           a=n-(i-1)*i/2;           b=i-a+1;        }        else        {            b=n-(i-1)*i/2;            a=i-b+1;        }        cout<<a<<'/'<<b<<endl;    }    return 0;}