High precision algorithm package based on class and object

High precision formula (don’t ask me where it comes from, you can’t find it on the Internet because this is what I wrote)

🙂

1. High-precision addition: add to carry and go to zero
2. High-precision subtraction: judge to subtract and go to zero
3. High-precision multiplication: multiply to estimate and then go to zero
4. High-low precision multiplication: multiply to carry and go to zero

#include

#include

using namespace std;



class BIGINT{

 public:

 int num[505];

 int length;

 bool positive;

 BIGINT(string str=""){

 memset(num, 0, sizeof(num));

 positive = true;

 if(str == ""){

 return;

}

 else{

 length = str.length();

 for(int i = 0; i){

 num[i] = str[str.length()-i-1]-'0';

}

}

}

 void show(){

 if(positive == false){

 cout<<"-";

}

 for(int i = length-1; i>=0; i--){

 cout<<num[i];

}

}

};



int compare(BIGINT &a,BIGINT &b){

 if(a.length > b.length){

 return 1;

}

 else if(a.length < b.length){

 return -1;

}

 else{

 int maxlen = max(a.length,b.length);

 for(int i = maxlen-1; i>=0; i--){

 if(a.num[i] > b.num[i ]){

 return 1;

}

 else if(a.num[i] <  b.num[i]){

 return -1;

}

}

 return 0;

}

}



BIGINT bigadd(BIGINT &a,BIGINT &b){

 BIGINT c;

 int maxlen = max(a.length,b.length);

 //Add

 for(int i = 0;i){

 c.num[i] = a.num[i] + b.num[i];

}

 //carry

 for(int i = 0;i){

 if(c.num[i]>=10){

 c.num[i+1] += 1;

 c.num[i] = c.num[i]% 10;

}

}

 //Go to zero

 if(c.num[maxlen] == 0){

 c.length = maxlen;

}

 else{

 c.length = maxlen + 1;

}

 return c;

}



BIGINT bigminus(BIGINT &a,BIGINT &b){

 BIGINT c;

 int maxlen = max(a.length,b.length);

 //Judge

 int maxint = compare(a,b);

 if(maxint == 1){

 //Subtract

 for(int i = 0;i){

 if(a.num[i]>=b.num[ i]){

 c.num[i] = a.num[i] - b.num[i];

}

 else{

 a.num[i+1] -= 1;

 a.num[i] += 10;

 c.num[i] = a.num[i] - b.num[i];

}

}

}

 else if(maxint == -1){

 c = bigminus(b,a);

 c.positive = false;

}

 //Go to zero

 for(int i = maxlen+1;i>=0;i--){

 if(c.num[i] != 0){

 c.length = i+1;

 return c;

}

}

 c.length = 1;

 return c;

}



BIGINT bigmultiply(BIGINT &a,BIGINT &b){

 BIGINT c;

 //Multiply

 for(int i = 0;i){

 for(int j = 0;j){

 c.num[i+j] += a.num[i]*b.num[j];

 c.num[i+j+1] += c.num[i+j]/10;

 c.num[i+j] %= 10;

}

}

 //estimated

 int len = a.length + b.length;

 //Go to zero

 for(int i = len+1;i>=0;i--){

 if(c.num[i] != 0){

 c.length = i+1;

 return c;

}

}

 c.length = 1;

 return c;

}



BIGINT bigmultiplywithsmall(BIGINT a,int b){

 //Multiply

 for(int i = 0;i){

 a.num[i] *= b;

}

 //carry

 for(int i = 0;i1;i++){

 if(a.num[i]>=10){

 a.num[i+1] += a.num[i] / 10;

 a.num[i] %= 10;

}

}

 //Go to zero

 if(a.num[a.length] != 0< span style="color: #000000;">){

 a.length += 1;

}

 return a;

}



int main(){

 BIGINT a("111111111");

 BIGINT b("111111111");

 BIGINT tmp;



 tmp = bigadd(a,b);

 cout<<"High precision addition:";

 tmp.show();

 cout<<endl;



 tmp = bigminus(a,b);

 cout<<"High precision subtraction:";

 tmp.show();

 cout<<endl;



 tmp = bigmultiply(a,b);

 cout<<"High precision multiplication:";

 tmp.show();

 cout<<endl;



 tmp = bigmultiplywithsmall(a,100);

 cout<<"High and low precision multiplication:";

 tmp.show();

 cout<<endl;

}

High-precision calculations refer to the range of numbers involved in calculations Type, real type) can represent the range of operations. For example, find the sum of two 20,000-digit numbers. At this time, it is necessary to use high-precision algorithms.

#include

#include

using namespace std;



class BIGINT{

 public:

 int num[505];

 int length;

 bool positive;

 BIGINT(string str=""){

 memset(num, 0, sizeof(num));

 positive = true;

 if(str == ""){

 return;

}

 else{

 length = str.length();

 for(int i = 0; i){

 num[i] = str[str.length()-i-1]-'0';

}

}

}

 void show(){

 if(positive == false){

 cout<<"-";

}

 for(int i = length-1; i>=0; i--){

 cout<<num[i];

}

}

};



int compare(BIGINT &a,BIGINT &b){

 if(a.length > b.length){

 return 1;

}

 else if(a.length < b.length){

 return -1;

}

 else{

 int maxlen = max(a.length,b.length);

 for(int i = maxlen-1; i>=0; i--){

 if(a.num[i] > b.num[i ]){

 return 1;

}

 else if(a.num[i] <  b.num[i]){

 return -1;

}

}

 return 0;

}

}



BIGINT bigadd(BIGINT &a,BIGINT &b){

 BIGINT c;

 int maxlen = max(a.length,b.length);

 //Add

 for(int i = 0;i){

 c.num[i] = a.num[i] + b.num[i];

}

 //carry

 for(int i = 0;i){

 if(c.num[i]>=10){

 c.num[i+1] += 1;

 c.num[i] = c.num[i]% 10;

}

}

 //Go to zero

 if(c.num[maxlen] == 0){

 c.length = maxlen;

}

 else{

 c.length = maxlen + 1;

}

 return c;

}



BIGINT bigminus(BIGINT &a,BIGINT &b){

 BIGINT c;

 int maxlen = max(a.length,b.length);

 //Judge

 int maxint = compare(a,b);

 if(maxint == 1){

 //Subtract

 for(int i = 0;i){

 if(a.num[i]>=b.num[ i]){

 c.num[i] = a.num[i] - b.num[i];

}

 else{

 a.num[i+1] -= 1;

 a.num[i] += 10;

 c.num[i] = a.num[i] - b.num[i];

}

}

}

 else if(maxint == -1){

 c = bigminus(b,a);

 c.positive = false;

}

 //Go to zero

 for(int i = maxlen+1;i>=0;i--){

 if(c.num[i] != 0){

 c.length = i+1;

 return c;

}

}

 c.length = 1;

 return c;

}



BIGINT bigmultiply(BIGINT &a,BIGINT &b){

 BIGINT c;

 //Multiply

 for(int i = 0;i){

 for(int j = 0;j){

 c.num[i+j] += a.num[i]*b.num[j];

 c.num[i+j+1] += c.num[i+j]/10;

 c.num[i+j] %= 10;

}

}

 //estimated

 int len = a.length + b.length;

 //Go to zero

 for(int i = len+1;i>=0;i--){

 if(c.num[i] != 0){

 c.length = i+1;

 return c;

}

}

 c.length = 1;

 return c;

}



BIGINT bigmultiplywithsmall(BIGINT a,int b){

 //Multiply

 for(int i = 0;i){

 a.num[i] *= b;

}

 //carry

 for(int i = 0;i1;i++){

 if(a.num[i]>=10){

 a.num[i+1] += a.num[i] / 10;

 a.num[i] %= 10;

}

}

 //Go to zero

 if(a.num[a.length] != 0< span style="color: #000000;">){

 a.length += 1;

}

 return a;

}



int main(){

 BIGINT a("111111111");

 BIGINT b("111111111");

 BIGINT tmp;



 tmp = bigadd(a,b);

 cout<<"High precision addition:";

 tmp.show();

 cout<<endl;



 tmp = bigminus(a,b);

 cout<<"High precision subtraction:";

 tmp.show();

 cout<<endl;



 tmp = bigmultiply(a,b);

 cout<<"High precision multiplication:";

 tmp.show();

 cout<<endl;



 tmp = bigmultiplywithsmall(a,100);

 cout<<"High and low precision multiplication:";

 tmp.show();

 cout<<endl;

}