Week5
1. 将字符串反转后返回新字符串
input: "APCS"
return: "SCPA"
public String reverseStr(String str) {
String result = "";
for(int i=0; i<str.length(); i++) {
result = str.substring(i,i+1) + result;
}
return result;
}
2. 统计字符串中的空格数
input: "APCS ROCKS THE WORLD"
return: 3
public int countSpaces(String str) {
int count = 0;
while(str.indexOf(" ") != -1) {
count++;
str = str.substring(str.indexOf(" ")+1);
}
return count;
}
3. 返回正整数的因数个数
input: 15
return: 4(1,3,5,15)
public int countFactors(int num) {
int count = 0;
for(int i=1; i<=num; i++) {
if(num%i==0) {
count++;
}
}
return count;
}
4. 返回正整数的各位数码之和
input: 15
return: 6(1+5)
public int sumDigits(int num) {
int digit=0;
int sum = 0;
while(num > 0) {
digit = num % 10;
sum += digit;
num /= 10;
}
return sum;
}
Last updated