题目
题目大意就是给定T组数据，每组数据一个等式，等式包含一个单次四则运算，问给定等式在几进制下合法，不合法就输出-1.
简单模拟
这个题目直接模拟即可，进制最大只到16，所以暴力枚举每一种进制不会有任何问题。需要注意的是，最小的可能应该是所有数字字符中最大值+1，例如12+23=56中最大的字符为6，则其中最小可能进制为6，应该从6开始枚举。
除此以外需要注意的就是爆int问题，题目中提到等式长度不超过15位所以直接使用long long即可
由于java包装类处理字符串转指定进制较为方便，这个题目就是用java了
import java.util.Scanner;
public class Main {
static String as,bs,cs;
static char sign;
static boolean check(int redix) {
long a = Long.parseLong(as,redix);
long b = Long.parseLong(bs,redix);
long c = Long.parseLong(cs,redix);
switch(sign) {
case '+':return a + b == c;
case '-':return a - b == c;
case '*':return a * b == c;
case '/':return a % b != 0 ? false : a / b == c;
}
return false;
}
public static void main(String[] str) {
Scanner scan = new Scanner(System.in);
String equation;
int mi;
while(scan.hasNext()) {
equation = scan.next();
parse(equation);
mi = 1;
mi = Math.max(mi, getMi(as));
mi = Math.max(mi, getMi(bs));
mi = Math.max(mi, getMi(cs));
for(int i = mi + 1;i <= 16;i++) {
if(check(i)) {
System.out.println(i);
break;
}
if(i == 16) {
System.out.println(-1);
}
}
}
}
private static int getMi(String s) {
int mi = 1;
char[] c = s.toCharArray();
for(int i = 0;i < c.length;i++) {
if(c[i] >= '0' && c[i] <= '9') {
mi = Math.max(mi,c[i] - '0');
}else {
mi = Math.max(mi, c[i] - 'A' + 10);
}
}
return mi;
}
private static void parse(String equation) {
cs = equation.split("=")[1];
equation = equation.split("=")[0];
if(equation.indexOf('+') != -1){
as = equation.substring(0,equation.indexOf('+'));
bs = equation.substring(equation.indexOf('+') + 1,equation.length());
sign = '+';
}else if(equation.indexOf('-') != -1){
as = equation.substring(0,equation.indexOf('-'));
bs = equation.substring(equation.indexOf('-') + 1,equation.length());
sign = '-';
}else if(equation.indexOf('*') != -1) {
as = equation.substring(0,equation.indexOf('*'));
bs = equation.substring(equation.indexOf('*') + 1,equation.length());
sign = '*';
}else if(equation.indexOf('/') != -1) {
as = equation.substring(0,equation.indexOf('/'));
bs = equation.substring(equation.indexOf('/') + 1,equation.length());
sign = '/';
}
// System.out.println(as + " " + bs + " " + cs);
}
}