Stack
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| class Solution {
public int alternateDigitSum(int n) {
Stack<Integer> stack = new Stack<>();
while (n > 0) {
int num = n % 10;
n /= 10;
stack.push(num);
}
int res = 0;
int sign = 1;
while (!stack.isEmpty()) {
res += sign * stack.pop();
sign *= -1;
}
return res;
}
}
|
Math
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| class Solution {
public int alternateDigitSum(int n) {
int res = 0;
int sign = 1;
while (n > 0) {
int num = n % 10;
res += sign * num;
n /= 10;
sign *= -1;
}
return -sign * res;
}
}
|
References
2544. Alternating Digit Sum