poj2190

简单题

View Code

#include <iostream>
#include <cstdlib>
#include <cstring>
#include <cstdio>
using namespace std;

char st[20];

int main()
{
//freopen("t.txt", "r", stdin);
gets(st);
int ans = 0;
int pos = 0;
for (int i = 0; i < 10; i++)
if (st[i] == '?')
pos = 10 - i;
else if (st[i] == 'X')
ans += 10 * (10 - i);
else
ans += (st[i] - '0') * (10 - i);
for (int i = 0; i <= 9; i++)
if ((ans + i * pos) % 11 == 0)
{
printf("%d\n", i);
return 0;
}
if ((ans + 10 * pos) % 11 == 0 && pos == 1)
{
printf("X\n");
return 0;
}
printf("-1\n");
return 0;
}

转载于:https://www.cnblogs.com/rainydays/archive/2011/06/05/2073184.html