C++ 代码
class Solution {
public:
int duplicateInArray(vector<int>& nums) {
int n = nums.size();
for(auto x:nums)
{
if (x < 0 || x >= n)
return -1;
}
for(int i=0; i<nums.size(); i++)
{
int ind = nums[i]%n;
if(nums[ind] > n)
return ind;
else
nums[ind] += n;
}
return -1;
}
};