include<stdio.h>#include<stdlib.h>#include"string.h"#define len 20int main(){int i,j,t,n,temp;char mult1[len];char mult2[len];printf("Input two big numbers:\n");scanf("%s %s",mult1,mult2);int len1 = strlen(mult1);int len2 = strlen(mult2);int *c1 = (int ...