846. Hand of Straights

Alice has a `hand` of cards, given as an array of integers.

Now she wants to rearrange the cards into groups so that each group is size `W`, and consists of `W` consecutive cards.

Return `true` if and only if she can.

Example 1:

``````Input: hand = [1,2,3,6,2,3,4,7,8], W = 3
Output: true
Explanation: Alice's hand can be rearranged as [1,2,3],[2,3,4],[6,7,8]
``````

Example 2:

``````Input: hand = [1,2,3,4,5], W = 4
Output: false
Explanation: Alice's hand can't be rearranged into groups of 4
``````

Note:

1. `1 <= hand.length <= 10000`
2. `0 <= hand[i] <= 10^9`
3. `1 <= W <= hand.length`

1 2 2 3 3 4 6 7 8

2 3 4 6 7 8

6 7 8

``````class Solution {
public:
bool isNStraightHand(vector<int>& hand, int W) {
map<int, int> m;
for (int i : hand) ++m[i];
while (!m.empty()) {
int start = m.begin()->first;
for (int i = 0; i < W; ++i) {
if (!m.count(start + i)) return false;
if (--m[start + i] == 0) m.erase(start + i);
}
}
return true;
}
};
``````

``````class Solution {
public:
bool isNStraightHand(vector<int>& hand, int W) {
map<int, int> m;
for (int i : hand) ++m[i];
for (auto a : m) {
if (a.second == 0) continue;
for (int i = a.first; i < a.first + W; ++i) {
if (m[i] < a.second) return false;
m[i] = m[i] - a.second;
}
}
return true;
}
};
``````

Github 同步地址：

https://github.com/grandyang/leetcode/issues/846

https://leetcode.com/problems/hand-of-straights/

https://leetcode.com/problems/hand-of-straights/discuss/135700/Short-Java-solution!

https://leetcode.com/problems/hand-of-straights/discuss/135598/C%2B%2BJavaPython-O(MlogM)-Complexity

LeetCode All in One 题目讲解汇总(持续更新中…)

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