範例程式碼 uva10106
//uva10106
#include<iostream>
#include<cstdio>
using namespace std;
int main() {
string input;
int X[255] = {0}, Y[255] = {0};
int xlen, ylen, anslen;
while(getline(cin, input)) {
xlen = input.length();
for(int i = 0; i < xlen; i++)
X[i] = input[xlen - i - 1] - '0';
getline(cin, input);
ylen = input.length();
for(int i = 0; i < ylen; i++)
Y[i] = input[ylen - i - 1] - '0';
int answer[510] = {0};
for(int i = 0; i < xlen; i++) {
for(int j = 0; j < ylen; j++) {
answer[i + j] += X[i] * Y[j];
answer[i + j + 1] += answer[i+j] / 10;
answer[i + j] %= 10;
}
}
anslen = xlen + ylen;
while(anslen > 1 && !answer[anslen - 1])
anslen--;
for(int i = anslen-1; i >= 0; i--)
printf("%d", answer[i]);
printf("\n");
}
return 0;
}