# 539. Minimum Time Difference

## Description

Given a list of 24-hour clock time points in "HH:MM" format, return the minimum minutes difference between any two time-points in the list.

Example 1:

Input: timePoints = ["23:59","00:00"]
Output: 1


Example 2:

Input: timePoints = ["00:00","23:59","00:00"]
Output: 0


Constraints:

• 2 <= timePoints.length <= 2 * 104
• timePoints[i] is in the format "HH:MM".

## Solutions

1. Convert all the times into minutes values mins, i.e. 13:14 => 13 * 60 + 14.
2. Sort the mins.
3. Push the time mins[0] + 24 * 60 to deal with min and max diff.
4. For each value in mins[1:], calculate the min diff mins[i] - mins[i - 1].
• class Solution {
public int findMinDifference(List<String> timePoints) {
if (timePoints.size() > 24 * 60) {
return 0;
}
List<Integer> mins = new ArrayList<>();
for (String t : timePoints) {
String[] time = t.split(":");
}
Collections.sort(mins);
int res = 24 * 60;
for (int i = 1; i < mins.size(); ++i) {
res = Math.min(res, mins.get(i) - mins.get(i - 1));
}
return res;
}
}

• class Solution {
public:
int findMinDifference(vector<string>& timePoints) {
if (timePoints.size() > 24 * 60)
return 0;
vector<int> mins;
for (auto t : timePoints)
mins.push_back(stoi(t.substr(0, 2)) * 60 + stoi(t.substr(3)));
sort(mins.begin(), mins.end());
mins.push_back(mins[0] + 24 * 60);
int res = 24 * 60;
for (int i = 1; i < mins.size(); ++i)
res = min(res, mins[i] - mins[i - 1]);
return res;
}
};

• '''
>>> a = "000"
>>> int(a)
0

>>> a = "00011"
>>> int(a)
11
'''
class Solution:
def findMinDifference(self, timePoints: List[str]) -> int:
if len(timePoints) > 24 * 60:
return 0
mins = sorted(int(t[:2]) * 60 + int(t[3:]) for t in timePoints)
mins.append(mins[0] + 24 * 60) # make it a circle, linking 1st and last slot

return min(abs(a - b) for a, b in pairwise(mins))

# below also works, same logic
# res = mins[-1]
# for i in range(1, len(mins)):
#     res = min(res, mins[i] - mins[i - 1])
# return res

############

class Solution(object):
def findMinDifference(self, timePoints):
"""
:type timePoints: List[str]
:rtype: int
"""
ans = 24 * 60
times = [0] * len(timePoints)
for i, time in enumerate(timePoints):
h, m = map(int, time.split(":"))
times[i] = h * 60 + m

times.sort()

for i in range(len(times) - 1):
ans = min(ans, abs(times[i] - times[i + 1]))
return min(ans, 1440 - abs(times[0] - times[-1]))


• func findMinDifference(timePoints []string) int {
if len(timePoints) > 24*60 {
return 0
}
var mins []int
for _, t := range timePoints {
time := strings.Split(t, ":")
h, _ := strconv.Atoi(time[0])
m, _ := strconv.Atoi(time[1])
mins = append(mins, h*60+m)
}
sort.Ints(mins)
mins = append(mins, mins[0]+24*60)
res := 24 * 60
for i := 1; i < len(mins); i++ {
res = min(res, mins[i]-mins[i-1])
}
return res
}

• function findMinDifference(timePoints: string[]): number {
const mins = timePoints
.map(item => Number(item.slice(0, 2)) * 60 + Number(item.slice(3, 5)))
.sort((a, b) => a - b);
const n = mins.length;
let res = Infinity;
for (let i = 0; i < n - 1; i++) {
res = Math.min(res, mins[i + 1] - mins[i]);
}

const first = mins[0] + 24 * 60;
const last = mins[n - 1];
res = Math.min(res, first - last);

return res;
}


• impl Solution {
pub fn find_min_difference(time_points: Vec<String>) -> i32 {
if time_points.len() > 1440 {
return 0;
}

let n = time_points.len();
let mut nums: Vec<i32> = Vec::with_capacity(n + 1);

for time in time_points.iter() {
let parts: Vec<i32> = time.split(':').map(|s| s.parse().unwrap()).collect();
let minutes = parts[0] * 60 + parts[1];
nums.push(minutes);
}

nums.sort();
nums.push(nums[0] + 1440);

let mut ans = i32::MAX;
for i in 1..=n {
ans = ans.min(nums[i] - nums[i - 1]);
}

ans
}
}


• class Solution {
func findMinDifference(_ timePoints: [String]) -> Int {
if timePoints.count > 1440 {
return 0
}

var nums = [Int]()

for t in timePoints {
let time = t.split(separator: ":").map { Int(\$0)! }
nums.append(time[0] * 60 + time[1])
}

nums.sort()
nums.append(nums[0] + 1440)

var ans = Int.max
for i in 1..<nums.count {
ans = min(ans, nums[i] - nums[i - 1])
}

return ans
}
}