1 #include<iostream> 2 #include<string.h> 3 #define MAX 100 4 void change(char *st , int len); 5 using namespace std; 6 7 8 int main() 9 {10 char st1[MAX] , st2[MAX];11 int st3[2*MAX] = {0};12 scanf("%s%s" , st1 , st2);13 int len1 , len2 , len3;14 int i , j;15 len1 = strlen(st1);16 len2 = strlen(st2);17 change(st1 , len1); //将数字翻转18 change(st2 , len2);19 for(i = 0; i < len1; i++) //大数乘法核心代码20 {21 for(j = 0; j < len2; j++)22 {23 st3[i+j] += (st1[i]-'0')*(st2[j]-'0');24 st3[i+j+1] += st3[i+j] / 10;25 st3[i+j] %= 10;26 }27 }28 len3 = len1+len2+1;29 while(!st3[len3])30 {len3--;}31 for(i = len3; i >= 0; i--) //输出32 cout<<st3[i];33 cout<<endl;34 return 0;35 }36 37 void change(char *st , int len)38 {39 int i , j;40 char temp;41 for(i =0, j = len-1; i <= j; i++, j--)42 {43 temp = st[i];44 st[i] = st[j];45 st[j] = temp;46 }47 }
