1005 大数加法

  1 #include <iostream>
  2 #include <cstring>
  3 #include <bits/stdc++.h>
  4 using namespace std;
  5 
  6 string bigadd(string s,string ss){
  7     string tt;
  8     int slen = s.length();
  9     int sslen = ss.length();
 10     reverse(s.begin(),s.end());
 11     reverse(ss.begin(),ss.end());
 12     int index = 0;
 13     for(int i=0;i<min(slen,sslen);i++){
 14         int a = s[i]-‘0‘,b = ss[i]-‘0‘;
 15         int at = a+b+index;
 16         if(at>9){
 17             tt+=at-10+‘0‘;
 18             index = 1;
 19         }else{
 20             tt+=at+‘0‘;
 21             index = 0;
 22         }
 23     }
 24     for(int i=min(slen,sslen);i<max(slen,sslen);i++){
 25         if(slen>i){
 26             int a = s[i]-‘0‘;
 27             int at = a+index;
 28             if(at>9){
 29                 tt+=at-10+‘0‘;
 30                 index = 1;
 31             }else{
 32                 tt+=at+‘0‘;
 33                 index = 0;
 34             }
 35         }else{
 36             int b = ss[i]-‘0‘;
 37             int at = b+index;
 38             if(at>9){
 39                 tt+=at-10+‘0‘;
 40                 index = 1;
 41             }else{
 42                 tt+=at+‘0‘;
 43                 index = 0;
 44             }
 45         }
 46     }
 47     if(index){
 48         tt+=‘1‘;
 49     }
 50     reverse(tt.begin(),tt.end());
 51     return tt;
 52 }
 53 
 54 string bigdel(string s,string ss){//s>=ss
 55     string tt,st;
 56     int slen = s.length();
 57     int sslen = ss.length();
 58     reverse(s.begin(),s.end());
 59     reverse(ss.begin(),ss.end());
 60     int index = 0;
 61     for(int i=0;i<sslen;i++){
 62         int a = s[i]-‘0‘;
 63         int b = ss[i]-‘0‘;
 64         int at = a-b-index;
 65         if(at<0){
 66             tt+=at+10+‘0‘;
 67             index = 1;
 68         }else{
 69             tt+=at+‘0‘;
 70             index = 0;
 71         }
 72     }
 73     for(int i=sslen;i<slen;i++){
 74         int b = s[i]-‘0‘;
 75         int at = b - index;
 76         if(at<0){
 77             tt+=at+10+‘0‘;
 78             index = 1;
 79         }else{
 80             tt+=at+‘0‘;
 81             index = 0;
 82         }
 83     }
 84     bool prime = true;
 85     for(int i = slen-1;i>=0;i--){
 86         if(tt[i]!=‘0‘){
 87             prime = false;
 88         }
 89         if(!prime){
 90             st+=tt[i];
 91         }
 92     }
 93     if(st.length()==0)
 94         st+=‘0‘;
 95     return st;
 96 }
 97 
 98 int compare(string s,string ss){
 99     int slen = s.length();
100     int sslen = ss.length();
101     if(slen==sslen){
102         for(int i=0;i<slen;i++){
103             if(s[i]==ss[i]){
104                 continue;
105             }else{
106                 return s[i]>ss[i];
107             }
108         }
109     }else{
110         return slen > sslen;
111     }
112     return 2;
113 }
114 string s,ss;
115 int main(){
116     while(cin>>s>>ss){
117         bool sflag=true, ssflag=true;
118         if(s[0]==‘-‘){
119             s.erase(0,1);
120             sflag = false;
121         }
122         if(ss[0]==‘-‘){
123             ss.erase(0,1);
124             ssflag = false;
125         }
126         if((sflag&&ssflag)||(!sflag&&!ssflag)){
127             string st = bigadd(s,ss);
128             if(sflag)
129                 cout<<st<<endl;
130             else{
131                 st=‘-‘+st;
132                 cout<<st<<endl;
133             }
134         }else{
135             string st;
136             if(sflag){//s为正数
137                 if(compare(s,ss)==0){
138                     st = bigdel(ss,s);
139                     st=‘-‘+st;
140                     cout<<st<<endl;
141                 }else if(compare(s,ss)==1){
142                     st = bigdel(s,ss);
143                     cout<<st<<endl;
144                 }else{
145                     cout<<"0"<<endl;
146                 }
147             }else{//ss为正数
148                 if(compare(s,ss)==0){
149                     st = bigdel(ss,s);
150                     cout<<st<<endl;
151                 }else if(compare(s,ss)==1){
152                     st = bigdel(s,ss);
153                     st=‘-‘+st;
154                     cout<<st<<endl;
155                 }else{
156                     cout<<"0"<<endl;
157                 }
158             }
159         }
160     }
161     return 0;
162 }

 1 import java.util.*;
 2 import java.io.*;
 3 import java.lang.String;
 4 import java.math.BigDecimal;
 5  
 6 public class p1036
 7 {
 8     public static void main(String[] args)
 9     {
10         String s1,s2;
11         Scanner cin = new Scanner(System.in);        
12         s1 = cin.next();
13         s2 = cin.next();
14         BigDecimal b1 = new BigDecimal(s1);
15         BigDecimal b2 = new BigDecimal(s2);
16         System.out.println(b1.add(b2));
17         cin.close();
18     }
19 }