高精度加法
#include<iostream>
#include<string>
#include<algorithm>
using namespace std;
string _add(string s1,string s2);
int main()
{string a,b;cin>>a>>b;cout<<_add(a,b);return 0;
}
string _add(string s1,string s2)
{reverse(s1.begin(),s1.end());reverse(s2.begin(),s2.end());int a[1000] = {0};int b[1000] = {0};int c[1000] = {0};int l1 = s1.size();int l2 = s2.size();for(int i = 0;i<l1;i++){a[i] = s1[i] - 48;}for(int i = 0;i<l2;i++){b[i] = s2[i] - 48;}for(int i = 0;i<max(l1,l2);i++){c[i] = a[i] + b[i];}for(int i = 0;i<max(l1,l2);i++){if(c[i]>=10){c[i+1] = c[i+1]+1;c[i] = c[i] - 10;}}int p = -1;for(int i = max(l1,l2)+1;i>=0;i--){if(c[i]!=0){p = i;break;}}if(p == -1) return "0";string res = "";for(int i = p;i>=0;i--){res = res + (char)(c[i]+48);}return res;
}
高精度减法
#include<iostream>
#include<string>
#include<algorithm>
using namespace std;
string _jian(string s1,string s2);
bool cmp(string s1,string s2);
int main()
{string a,b;cin>>a>>b;cout<<_jian(a,b);return 0;
}
bool cmp(string s1,string s2)
{if(s1.size() == s2.size()) return s1>s2;else return s1.size()>s2.size();
}
string _jian(string s1,string s2)
{string op = "";bool f = cmp(s1,s2);if(f == false){op = "-";swap(s1,s2);}reverse(s1.begin(),s1.end());reverse(s2.begin(),s2.end());int a[1000] = {0};int b[1000] = {0};int c[1000] = {0};int l1 = s1.size();int l2 = s2.size();for(int i = 0;i<l1;i++){a[i] = s1[i]-48;}for(int i = 0;i<l2;i++){b[i] = s2[i]-48;}for(int i = 0;i<l1;i++){c[i] = a[i] - b[i];}for(int i = 0;i<l1;i++){if(c[i]<0){c[i+1] = c[i+1]-1;c[i] = c[i] + 10;}}int p = -1;for(int i = l1;i>=0;i--){if(c[i]!=0){p = i;break;}}string res = op;for(int i = p;i>=0;i--){res = res + (char)(c[i]+48);}return res;
}
高精度乘法
#include<iostream>
#include<string>
#include<algorithm>
using namespace std;
string _cheng(string s1,string s2);
int main()
{string a,b;cin>>a>>b;cout<<_cheng(a,b);return 0;
}
string _cheng(string s1,string s2)
{reverse(s1.begin(),s1.end());reverse(s2.begin(),s2.end());int a[1000]={0};int b[1000]={0};int c[2000]={0};int l1 = s1.size();int l2 = s2.size();for(int i = 0;i<l1;i++){a[i] = s1[i]-48;}for(int i = 0;i<l2;i++){b[i] = s2[i]-48;}for(int i = 0;i<l1;i++){for(int j = 0;j<l2;j++){c[i+j] = c[i+j] + a[i]*b[j];}}for(int i = 0;i<l1+l2;i++){if(c[i]>=10){c[i+1] = c[i+1] + c[i]/10;c[i] = c[i]%10;}}int p = -1;for(int i = l1+l2;i>=0;i--){if(c[i]!=0){p = i;break;}}if(p == -1) return "0";string res = "";for(int i = p;i>=0;i--){res = res + (char)(c[i]+48);}return res;
}
高精度除法
#include<iostream>
#include<string>
#include<algorithm>
using namespace std;
string _chu(int a,int b,int k);
int main()
{int c,d,e;cin>>c>>d>>e;cout<<_chu(c,d,e);return 0;
}
string _chu(int a,int b,int k)
{string res = "";if(k==0) res = to_string(a/b);else res = to_string(a/b)+".";for(int i = 0;i<k;i++){a = a%b*10;res = res + to_string(a/b);}return res;
}
