【十二题解】 | #高精度整数加法#

#include<stdio.h>

int main(){

char num1[1000]={0};
char num2[1000]={0};
while(scanf("%s", num1) != EOF){
    scanf("%s", num2);
    int len1, len2;
    for(len1=0; num1[len1] != '\0'; len1++);
    for(len2=0; num2[len2] != '\0'; len2++);
    char ans[1000]={0};
    int loc = 999;
    int min=len1<len2?len1:len2;
    int max=len1>len2?len1:len2;
    int leijia=0;
    int x=len1-1;
    int y=len2-1;
    for(; max>0; max--){
        int sign =0;
        int he;
        if(x>=0 && y>=0){
             he=num1[x]+num2[y]-'0'-'0'+leijia;
        }
        else if(x>=0){
            he=num1[x]-'0'+leijia;
        }
        else{
            he=num2[y]-'0'+leijia;
        }
        if(he>=10){
            sign = 1;
            he%=10;
        }
        ans[loc]=he+'0';
        x--;
        y--;
        loc--;
        leijia=sign==1?1:0;
    }
    if(leijia == 1){
        ans[loc++]=leijia+'0';
    }
    int start;
    for(start=0; ans[start]=='\0'; start++);
    for(; start<1000; start++){
        printf("%c", ans[start]);
    }
    printf("\n");
}

}