1653 - Minimum Deletions to Make String Balanced

 JAVA

• class Solution {
      public int minimumDeletions(String s) {
          int n = s.length();
          int[] f = new int[n + 1];
          int b = 0;
          for (int i = 1; i <= n; ++i) {
              if (s.charAt(i - 1) == 'b') {
                  f[i] = f[i - 1];
                  ++b;
              } else {
                  f[i] = Math.min(f[i - 1] + 1, b);
              }
          }
          return f[n];
      }
  }

C++

• class Solution {
  public:
      int minimumDeletions(string s) {
          int n = s.size();
          int f[n + 1];
          memset(f, 0, sizeof(f));
          int b = 0;
          for (int i = 1; i <= n; ++i) {
              if (s[i - 1] == 'b') {
                  f[i] = f[i - 1];
                  ++b;
              } else {
                  f[i] = min(f[i - 1] + 1, b);
              }
          }
          return f[n];
      }
  };