//-, +, * and / without them // unary operators allowed // by baptiste prunier #include int add(int a,int b); int sub(int a,int b); int minus(int i); int div(int a,int b); int mult(int a,int b); int main() { int i, j; puts("SUM TESTS\n---------"); for(i = -4;i<4;++i){ for(j = -4;j<4;++j){ printf("%d + %d = %d\n",i,j,add(i,j)); } } puts("\nSUBSTRACTION TESTS\n------------------"); for(i = -4;i<4;++i){ for(j = -4;j<4;++j){ printf("%d - %d = %d\n",i,j,sub(i,j)); } } puts("\nMULTIPLICATION TESTS\n--------------------"); for(i=0;i<=10;++i){ printf("%d * %d = %d\n",i,i,mult(i,i)); } puts("\nDIVISION TESTS\n--------------"); for(i=2;i<6;++i){ for(j=7;j<=12;++j){ printf("%d / %d = %d\n",j,i,div(j,i)); } } return 0; } /* ---------------------------------- */ /* FUNCTION DEFINITION */ int add(int a,int b){ int res = 0; unsigned bit = 1; int rest = 0; if(a<0){ res=sub(b,minus(a)); }else if(b<0){ res=sub(a,minus(b)); }else{ if(b>a){ a^=b^=a^=b; } while(bit<=b && bit){ if(a&bit && b&bit){ if(rest){ res=res|bit; } rest=1; }else if(a&bit || b&bit){ if(!rest){ res=res|bit; } }else if(rest){ res=res|bit; rest=0; } bit<<=1; } while(bit<=a && bit){ if(a&bit && !rest){ res=res|bit; }else if(!(a&bit) && rest){ res=res|bit; rest=0; } bit<<=1; } if(rest){ res=res|bit; } } return res; } int sub(int a,int b){ int res = 0; unsigned bit = 1; int rest = 0; if(a<0){ res=minus(add(minus(a),b)); }else if(b<0){ res=add(a,minus(b)); }else if(b>a){ res=minus(sub(b,a)); }else{ while(bit<=b && bit){ if(a&bit && b&bit){ if(rest){ res=res|bit; } rest=0; }else if(a&bit || b&bit){ if(!rest){ if(b&bit){ rest=1; } res=res|bit; } }else if(rest){ res=res|bit; } bit<<=1; } while(bit<=a && bit){ if(a&bit && rest){ rest=0; }else if(a&bit || rest){ res=res|bit; } bit<<=1; } if(rest){ res=res|bit; } } return res; } int minus(int i){ int res=0; unsigned long bit=1; int rest=1; if(i<0){ //i-1 while(bit){ if((i&bit && !rest)||(!(i&bit) && rest)){ res|=bit; }else{ rest=0; } bit<<=1; } //1's complement res=~res; }else if(i>0){ //1's complement i=~i; //i+1 bit=1; while(bit){ if((i&bit && !rest)||(!(i&bit) && rest)){ res|=bit; rest=0; } bit<<=1; } } return res; } int div(int b,int c){ int res=0; int signe = 1; unsigned bit=1; if(c<0){ signe=-1; c=minus(c); } if(b<0){ signe=(signe==1?-1:1); b=minus(b); } bit=1; while(c>=1; bit>>=1; if(cb){ b^=c^=b^=c; } if(c<0){ signe=-1; c=minus(c); } if(b<0){ signe=(signe==1?-1:1); b=minus(b); } while(c){ if(c&1) { res|=b; } b>>=1; c>>=1; } return (signe==1?res:minus(res)); }

+ - * / without them