Algorithm to improve P1001

When two larger integers are multiplied, a data overflow scenario may Occur. To avoid overflow, you can use a string method to achieve multiplication between two large numbers. specifically, first enter two integers as strings, each integer will not exceed 8 bits in length, and then the result of multiplying them is stored in another string (no more than 16 bits in length), and finally the string is printed Out. For example, Suppose the user input is: 62773417 and 12345678, the output is: 774980393241726.

Input:
62773417 12345678

Output:
774980393241726

The main thing to note is the question of rounding ....

#include <stdio.h>#include<string.h>voidMultiply (Char*s,Char*s1,Char*S2) {    intlen,len1,i,j,k,count,tmp;//Count: RoundingLen = strlen (s), len1 =strlen (s1);  for(i =0; I < -; i + +) s2[i]='0';//you can't use memset .s2[ -] =' /';  for(j = len1-1; J >=0; j--) {count=0; K= len1-j-1;//note where each round starts to be placed         for(i = len-1; I >=0; i--) {tmp= (s1[j]-'0') * (s[i]-'0') +count; if(tmp + s2[k]-'0'>9){                //count and s2[k] are mutually affected, solution I sets a variable, II calculates the count into TMP before doing the If Judgment//still note that count is calculated before s2[k]//count = (tmp + count + s2[k]-' 0 ')/10;//s2[k] = (tmp + count + s2[k]-' 0 ')%10 + ' 0 ';Count = (tmp + s2[k]-'0')/Ten; s2[k]= (tmp + s2[k]-'0')%Ten+'0'; }            Else{s2[k]= tmp +s2[k]; Count=0; } k++; }        if(count >0) s2[k]= Count +'0'; }    //the following method can only avoid the last 0, the final output is to start at non-0 o'clock output//the simpler way is to define the global variables in k, so it is not necessary to strlen for length at output time.    if(! (s2[k] >'0'|| s2[k] = =' /')) s2[k]=' /'; Else if(s2[k] >'0') {s2[k+1] =' /'; }    }intmain () {Chars[9],s1[9],s2[ -]; inti,j; scanf ("%s%s", s,s1);    Multiply (s,s1,s2); //Reverse Output     for(i = strlen (s2)-1; I >=0; i-- )        if(s2[i]! ='0')              break; if(i = =-1) Putchar ('0');//0 to consider separately     for(j = i; J >=0; j--) Putchar (s2[j]); Puts (""); return 0;}

Algorithm to improve P1001