题目解析
输出 2 占 总数字字符的比例 且 负数多0.5倍 偶数再加1倍
解题思路
暴力枚举字符串中含有多少个二 再利用题意求出答案即可
切记 '-' 不算在总长度中
代码
import java.io.*;
import java.util.*;
public class Main
{
public static void main(String[] args)
{
char s[] = sc.next().toCharArray();
int len = s.length;
double cd = 1;
boolean fu = false;
if (s[0] == '-')
{
cd += 0.5;
fu = true;
}
if (((s[len - 1] - '0') & 1) == 0)
cd *= 2;
int two = 0;
for (int i = 0; i < len; i++)
{
if (s[i] == '2')
two++;
}
if (fu)
len--;
double ans = two * 1.0 / len * cd;
out.printf("%.2f%%\n", ans * 100);
out.flush();
out.close();
}
static Scanner sc = new Scanner(System.in);
static PrintWriter out = new PrintWriter(System.out);
}