Skip to content

926. Flip String to Monotone Increasing 👍

  • Time:
  • Space:
 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
class Solution {
 public:
  int minFlipsMonoIncr(string S) {
    vector<int> dp(2);

    for (int i = 0; i < S.length(); ++i) {
      int temp = dp[0] + (S[i] == '1');
      dp[1] = min(dp[0], dp[1]) + (S[i] == '0');
      dp[0] = temp;
    }

    return min(dp[0], dp[1]);
  }
};
 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
class Solution {
  public int minFlipsMonoIncr(String S) {
    int[] dp = new int[2];

    for (int i = 0; i < S.length(); ++i) {
      int temp = dp[0] + (S.charAt(i) == '1' ? 1 : 0);
      dp[1] = Math.min(dp[0], dp[1]) + (S.charAt(i) == '0' ? 1 : 0);
      dp[0] = temp;
    }

    return Math.min(dp[0], dp[1]);
  }
}
1
2
3
4
5
6
7
8
class Solution:
  def minFlipsMonoIncr(self, S: str) -> int:
    dp = [0] * 2

    for i, c in enumerate(S):
      dp[0], dp[1] = dp[0] + (c == '1'), min(dp[0], dp[1]) + (c == '0')

    return min(dp[0], dp[1])