#include 
     
      #include "algorithm" #include "cmath"#include "string"#include 
      
        using namespace std;int main(){ int sav[8]={
   1,2,4,8,16,32,64,128};//2^n事先存储  int er[8]={
   0};//存储二进制01  int phigh=7; int cur=0; int sum=100; while(phigh>=0){ cur+=sav[phigh]; if(cur>sum){ cur-=sav[phigh]; //cout<<"情况1"<
       
        <
       
      
     

也可以不用事先存储：（只适合正整数求补码）

#include 
     
      #include "algorithm" #include "cmath"#include "string"#include 
      
        #include "bitset"using namespace std;int main(){//如果只是输出就不用事先存储了     int phigh=7; int cur=0; int num=0;//位数  int sum=100; while(phigh>=0){ cur+=pow(2,phigh); if(cur>sum){ cout<<0;num++;     cur-=pow(2,phigh); phigh--;//之前忽略了这个     } else if(cur==sum){      cout<<1;num++;      break; } else{     cout<<1;num++;     phigh--;   }} for(int i=1;i<=8-num;i++){
   //默认8位      cout<<0; }cout<
      
     

常规解法：（只适合正整数求补码）

#include 
     
      #include "algorithm" #include "cmath"#include "string"#include 
      
        using namespace std;int main(){int sum=100;vector
       
         res; while(sum){res.push_back(sum%2);sum=sum/2;        }reverse(res.begin(),res.end());for(vector
        
         ::iterator it=res.begin();it!=res.end();it++)cout<<*it; }
        
       
      
     

 库函数：//正负数都可以

#include
     
      #include
      
       #include
       
        using namespace std;int main(){    bitset<8> t=-125;    cout<