剑指 Offer 03. 数组中重复的数字
class Solution {
public:
int findRepeatNumber(vector<int>& nums) {
for(int ii = 0; ii < nums.size(); ii++) {
while(nums[ii] != ii) {
if(nums[ii] == nums[nums[ii]]) return nums[ii];
swap(nums[ii], nums[nums[ii]]);
}
}
return -1;
}
};
class Solution {
public:
int findRepeatNumber(vector<int>& nums) {
vector<bool> isExist(nums.size(), false);
for(auto num : nums) {
if(isExist[num]) return num;
isExist[num] = true;
}
return -1;
}
};
class Solution {
public:
int findRepeatNumber(vector<int>& nums) {
sort(nums.begin(), nums.end());
for(int ii = 1; ii <nums.size(); ii++) {
if(nums[ii] == nums[ii - 1]) return nums[ii];
}
return -1;
}
};