LeetCode Game 15 Game Fortnight

More than 25% of the number of elements in the array 1287. orderly appearance

1288. deleted covered range

1286. letter combinations iterator

1289. Minimum descending path and II

Fall and can not keep only a minimum of two original array, hacked.

More than 25% of the number of elements in the array 1287. orderly appearance

More than 25% of the number of elements in the array 1287. orderly appearance

To give you a non-decreasing order integer array, this array is known exactly an integer number of times it occurs more than 25% of the total number of array elements.

Please find and return the integer

Example:

**输入:** arr = [1,2,2,6,6,6,6,7,10]
**输出:** 6

Tip Hint

prompt:

  • 1 <= arr.length <= 10^4
  • 0 <= arr[i] <= 10^5

Code

class Solution {
public:
    int findSpecialInteger(vector<int>& arr) {
        int n = arr.size(),val = arr[0];
        pair<int,int>ans({0,0});
        for(int i = 0,c = 0;i < n;++i){
          if(arr[i] == val)  c++,ans=max(ans,make_pair(c,val));
          else c = 1,val = arr[i];
        }
        return ans.second;
    }
};

1288. deleted covered range

1288. deleted covered range

Give you a range list, you delete the interval list are covered by other sections.

Only if c <= aand b <= dwhen we believe that the interval [a,b)is the interval [c,d)covered.

After completing all the delete operation, you return to the list of the number of remaining range.

Example:

**输入:** intervals = [[1,4],[3,6],[2,8]]
**输出:** 2
**解释:** 区间 [3,6] 被区间 [2,8] 覆盖,所以它被删除了。

Tip Hint

Tips:

  • 1 <= intervals.length <= 1000
  • 0 <= intervals[i][0] < intervals[i][1] <= 10^5
  • For all i != j:intervals[i] != intervals[j]

Code

class Solution {
  typedef pair<int, int>PII;
 public:

  static bool cmp(vector<int>& a, vector<int>& b) {
    return (a[0] != b[0]) ? (a[0] < b[0]) : (a[1] > b[1]);
  }

  int removeCoveredIntervals(vector<vector<int>>& intervals) {
    const int n = intervals.size();
    sort(intervals.begin(), intervals.end(), cmp);
    int l = intervals[0][1], ans = 1;
    for(int i = 1; i < n; ++i) {
      if(intervals[i][1] > l)
        ans++, l = intervals[i][1];
    }
    return ans;
  }
};

1286. letter combinations iterator

1286. letter combinations iterator

You design an iterator class, including the following:

  • A constructor function, the input parameters comprising: a unique and ordered character string characters(the string contains only lowercase letters) and a number combinationLength.
  • Function Next () , according to the dictionary order to return the length of combinationLengththe next letter combination.
  • Function the hasNext () , there is only the length of combinationLengththe next letter combination, before returning True; otherwise, return False.

Example:

CombinationIterator iterator = new CombinationIterator("abc", 2); // 创建迭代器 iterator

iterator.next(); // 返回 "ab"
iterator.hasNext(); // 返回 true
iterator.next(); // 返回 "ac"
iterator.hasNext(); // 返回 true
iterator.next(); // 返回 "bc"
iterator.hasNext(); // 返回 false

Tip Hint

prompt:

  • 1 <= combinationLength <= characters.length <= 15
  • Each test contains up to 10^4twice the function call.
  • Topic ensure that each function calls nextare when the presence of a combination of letters.

Code

class CombinationIterator {
 public:
  string characters;
  string cur;
  int combinationLength;
  bool first;
  CombinationIterator(string characters, int combinationLength) {
    this->characters = characters;
    this->combinationLength = combinationLength;
    this->cur = characters.substr(0, combinationLength);
    this->first = true;
  }

  string next() {
    if(first) {
      first = false;
      return cur;
    }
    vector<int>pos;
    for(int i = 0; i < combinationLength; i++) {
      pos.push_back(characters.find_first_of(cur[i]));
    }
    for(int i = pos.size() - 1; i >= 0; --i) {
      if((i == pos.size() - 1 && pos[i] < characters.length() - 1)
          || (i < pos.size() - 1 && pos[i] + 1 != pos[i + 1])) {
        shiftPos(pos, i);
        break;
      }
    }
    cur = "";
    for(int i = 0, sz = pos.size(); i < sz; ++i)
      cur += characters[pos[i]];
    return cur;
  }

  void shiftPos(vector<int>&pos, int i) {
    pos[i]++;
    for(int j = i + 1; j < combinationLength; ++j)
      pos[j] = pos[j - 1] + 1;
  }

  bool hasNext() {
    vector<int>pos;
    for(int i = 0; i < combinationLength; i++) {
      pos.push_back(characters.find_first_of(cur[i]));
    }
    //for(auto i : pos) cout << i << " "; cout << endl;
    if(pos[0] == characters.length() - combinationLength)
      return false;
    return true;
  }
};

/**
 * Your CombinationIterator object will be instantiated and called as such:
 * CombinationIterator* obj = new CombinationIterator(characters, combinationLength);
 * string param_1 = obj->next();
 * bool param_2 = obj->hasNext();
 */

1289. Minimum descending path and II

1289. Minimum descending path and II

Give you a square integer arr, the definition of "non-zero offset decline path" as: from arrselecting a numeric array in each row, and the order of elected figures, the neighbors are not in the same column of the original array.

Please return to a non-zero offset of the minimum number and descending path.

Sample input and output sample Sample Input and Sample Output

Example 1:

**输入:** arr = [[1,2,3],[4,5,6],[7,8,9]]
**输出:** 13
**解释:**
所有非零偏移下降路径包括:
[1,5,9], [1,5,7], [1,6,7], [1,6,8],
[2,4,8], [2,4,9], [2,6,7], [2,6,8],
[3,4,8], [3,4,9], [3,5,7], [3,5,9]
下降路径中数字和最小的是 [1,5,7] ,所以答案是 13 。

Tip Hint

prompt:

  • 1 <= arr.length == arr[i].length <= 200
  • -99 <= arr[i][j] <= 99

Code

class Solution {
 public:
  static const int inf = 0x3f3f3f3f;
  int minFallingPathSum(vector<vector<int>>& arr) {
    int n = arr.size(), m = arr[0].size();
    int s[n][m];
    for(int j = 0; j < m; ++j)
      s[0][j] = arr[0][j];
    for(int i = 1; i < n; ++i) {
      for(int j = 0; j < m; ++j) {
        s[i][j] = inf;
        for(int k = 0; k < m; ++k) {
          if(k == j) continue;
          s[i][j] = min(s[i][j], s[i - 1][k] + arr[i][j]);
        }
      }
    }
    int ans = inf;
    for(int i = 0;i < m;++i) ans = min(ans,s[n-1][i]);
    return ans;
  }
};

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Origin www.cnblogs.com/Forgenvueory/p/12057652.html