Given a non-negative integer c, your task is to decide whether
there’re two integers a and b such that a2 + b2 = c.Example 1:
Input: 5 Output: True Explanation: 1 * 1 + 2 * 2 = 5
Example 2:
Input: 3 Output: False
双指针,0ms
class Solution {
public:
bool judgeSquareSum(int c) {
long int i = 0, j = round(sqrt(c)), temp;
while (i <= j) {
temp = i*i + j*j;
if (temp < c) {
++i;
}
else if (temp > c) {
--j;
}
else {
return true;
}
}
return false;
}
};