题解 | #高精度整数加法#
高精度整数加法
http://www.nowcoder.com/practice/49e772ab08994a96980f9618892e55b6
#include<stdio.h>
#include<string.h>
int add(int a,int b,int*carry_in){
int sum = a+b+*carry_in;
if(sum>9){
*carry_in = 1;
return sum-10;
}
else{
*carry_in = 0;
return sum;
}
}
int main(){
char s1[10000] = {0};
char s2[10000] = {0};
scanf("%s",s1);
scanf("%s",s2);
int len1 = strlen(s1);
int len2 = strlen(s2);
int len_max = len1>len2?len1:len2;
if(len1>len2){
int d = len1-len2;
for(int i=len2-1;i>=0;i--){
s2[i+d] = s2[i];
}
for(int i=0;i<d;i++){
s2[i] = '0';
}
}
else if(len1<len2){
int d = len2-len1;
for(int i=len1-1;i>=0;i--){
s1[i+d] = s1[i];
}
for(int i=0;i<d;i++){
s1[i] = '0';
}
}
int carry_in = 0;
int r;
int k=0;
char res[10001] = {0};
for(int i=len_max-1;i>=0;i--){
int a = s1[i]-48;
int b = s2[i]-48;
r = add(a,b,&carry_in);
res[k++] = r+48;
}
if(carry_in==1)
res[k++] = 49;
for(int i=k-1;i>=0;i--)
printf("%c",res[i]);
}
