C++ for ICPC

Read Until EOF




  while(getline(cin, data)) {

...

  }







Compare Strings




string a, b;

a.compare(b)







Set String To Upper

string word;

transform(word.begin(),word.end(),word.begin(),::toupper);




Append String

http://www.cplusplus.com/reference/string/string/append/

string (1)	string& append (const string& str);
substring (2)	string& append (const string& str, size_t subpos, size_t sublen);
c-string (3)	string& append (const char* s);
buffer (4)	string& append (const char* s, size_t n);
fill (5)	string& append (size_t n, char c);
range (6)	template <class InputIterator> string& append (InputIterator first, InputIterator last);
initializer list(7)	string& append (initializer_list<char> il);

Reverse String

string(word.rbegin(),word.rend())

When to use scanf or cin

small amount of input or cumbersome string input -> cin

big amount of input -> scanf

When to use printf or cout

small amount of output -> cout

big amount of output or printing double -> printf

Get Average

auto avg=accumulate(data.begin(),data.end(),0)/n;

Get Stdev

double avg;

double app(double x){return (x-avg)*(x-avg);}

void proc(){

  avg=data.sum()/n;

  double result=sqrt(data.apply(app).sum()/n);

  printf("%lf\n",result);

}

void proc(){

  ld avg=accumulate(data.begin(),data.end(),0.0)/n;

  transform(data.begin(),data.end(),data.begin(),[avg](ld x)->ld{return (x-avg)*(x-avg);});

  ld result=sqrt(accumulate(data.begin(),data.end(),0.0)/n);

  printf("%Lf\n",result);

}

Dice Library

struct Cube{

    /**

    *   0

    * 3 1 2 4

    *   5

    * <:y ^:x <>:z

    **/

    Cube(){}

    int d[6];

    void roll(int i,int j,int k,int l){

        int t=d[i];d[i]=d[j];d[j]=d[k];d[k]=d[l];d[l]=t;

    }

     

    void z(){roll(1,2,4,3);}

    void y(){roll(0,2,5,3);}

    void x(){roll(0,1,5,4);}

     

    void n(){x();}

    void s(){x(),x(),x();}

    void e(){y(),y(),y();}

    void w(){y();}

     

    int getRight(int top,int front){

        int right;

        for(int i=0;i<6;++i){

            for(int j=0;j<4;++j){

                if(d[0]==top&&d[1]==front)right=d[2];

                z();

            }

            if(i&1)x();

            else y();

        }

        return right;

    }

     

    bool isSame(Cube c){

        auto chk=[&]{for(int i=0;i<6;++i)if(d[i]!=c.d[i])return false;return true;};

        bool res=false;

        for(int i=0;i<6;++i){

            for(int j=0;j<4;++j){

                if(!res&&chk())res=true;

                z();

            }

            if(i&1)x();

            else y();

        }

        return res;

    }

};

Greatest Common Divisor

int gcd(int a,int b){

    do{

        int c=a%b;

        a=b;

        b=c;

    }while(b);

    return a;

}

Includes all of Standard Library Headers

#include <bits/stdc++.h> // g++ only