思路
这道题在我看来真是很水, 我的想法就是用一个变量C来记录当前要计算的字符, 用s表示该字符后面字符串的长度.那么要有写特例就是当s == 0的时候并不表示后面的数字长度为0,而是为1.给省略了.针对这个情况再做处理就行.
//
// Created by sixleaves on 2016/11/19.
//
#include
#include
#include
#define MAXSIZE 126
char input[MAXSIZE];
float moral(char ch) {
float m = 0.0;
switch (ch) {
case 'C':
m = 12.01;
break;
case 'H':
m = 1.008;
break;
case 'O':
m = 16.00;
break;
case 'N':
m = 14.01;
break;
default:
m = 0;
}
return m;
}
// read lenghth of len char starting from s
int readInt(char *in, int s, int len) {
if (0 == len) return 1;
char *p = in + s;
int v = 0;
for (int i = 0; i < len; i++) {
v = v * 10 + (*p - '0');
p++;
}
return v;
}
int main () {
int n;
while (scanf("%d", &n) == 1) {
for (int i = 0; i < n; i++) {
memset(input, 0, sizeof(input));
scanf("%s", input);
int len = strlen(input);
int s = 0, c = 0;
int v = 0;
float sum =0.0;
for (int j = 1; j < len; j++) {
if (isdigit(input[j])) {
s++;
}else {
sum += moral(input[c]) * readInt(input, c + 1, s);
s = 0;
c = j;
}
}
sum += moral(input[c]) * readInt(input, c + 1, s);
printf("%.3f\n", sum);
}
}
}
package CH3.ArraryAndStrings;
import java.util.Scanner;
/**
* Created by sixleaves on 2016/11/19.
*/
public class UVA1586 {
static float moral(char ch) {
float m = 0.0f;
switch (ch) {
case 'C':
m = 12.01f;
break;
case 'H':
m = 1.008f;
break;
case 'O':
m = 16.00f;
break;
case 'N':
m = 14.01f;
break;
default:
m = 0;
}
return m;
}
// read lenghth of len char starting from s
static int readInt(String in, int s, int len) {
if (0 == len) return 1;
int index = s;
int v = 0;
for (int i = 0; i < len; i++) {
v = v * 10 + (in.charAt(index) - '0');
index++;
}
return v;
}
static public void main(String...args) {
Scanner cin = new Scanner(System.in);
int n;
n = cin.nextInt();
String nextLine = cin.nextLine();
for (int i = 0; i < n; i++) {
String line = cin.nextLine();
int len = line.length();
int c = 0, s = 0;
float sum = 0.0f;
for (int j = 1; j < len; j++) {
if (Character.isDigit(line.charAt(j))) {
s++;
}else {
sum += moral(line.charAt(c)) * readInt(line, c + 1, s);
s = 0;
c = j;
}
}
if (line.length() >= 1)
sum += moral(line.charAt(c)) * readInt(line, c + 1, s);
System.out.println(String.format("%.3f", sum));
}
}
}
API:
- Java的Scanner再读取Int和String时候的注意事项.再调用nextInt后, 需要调用nextLine先把\n读掉, 此时读出来的是空行, 那是因为这个字符串确实是空的, 以\n直接结尾.如果是在Windows下就是\r\n.之后再使用nextLine读取字符串才能读到正确的值.
The problem is the
'\n'character that follows your integer. When you callnextInt, the scanner reads theint, but it does not consume the'\n'character after it;nextLinedoes that. That is why you get an empty line instead of the string that you were expecting to get.Let's say your input has the following data:
12345 helloHere is how the input buffer looks initially (
^represents the position at which theScannerreads the next piece of data):1 2 3 4 5 \n h e l l o \n ^After
nextInt, the buffer looks like this:1 2 3 4 5 \n h e l l o \n ^The first
nextLineconsumes the\n, leaving your buffer like this:1 2 3 4 5 \n h e l l o \n ^Now the
nextLinecall will produce the expected result. Therefore, to fix your program, all you need is to add another call tonextLineafternextInt, and discard its result:k = in.nextInt(); in.nextLine(); // Discard '\n' input = in.nextLine();
- Java中写的浮点型默认是double, 要加上f表示是float.
- Scanner和C中的scanf一样, 是阻塞方式的读取.