Dec18

Author: aliasvishnu

README.md

@@ -80,6 +80,7 @@ Solutions <a href = "https://github.com/aliasvishnu/leetcode/tree/master/Solutio
 | 119 | BF | Generate new row from old row. | O(n^2) |
 | 128 | DP | DP problem, find recurrence relation. | |
 | 413 | Array | [1, 2, 3, 4, 5, 7, 9, 11]. can be written as [5, 3] i.e. 5 sequence of difference 1 and 3 sequence of difference 2, you need to figure out how many parts you can split 5 and 3 into. | O(n) |
+| 738 | Array | Find the first time Xi > Xi+1, Xi -= 1 and turn all Xi+k = 9, For eg, 321 becomes 299. However if there are repeating digits like 33332, then subtract the first occurrence then rest become 9, 33332 becomes 29999. | O(n) |
 
 ## Second hint list
 

Solutions/738-MonotoneIncreasingDigits.cpp

@@ -0,0 +1,29 @@
+class Solution {
+public:
+    int monotoneIncreasingDigits(int N) {
+        vector<int> n;
+
+        while(N != 0){
+            n.push_back(N%10);
+            N /= 10;
+        }
+
+        reverse(n.begin(), n.end());
+
+        long answer = 0, len = n.size();
+        for(int i = 0; i < len-1; i++){
+            if(n[i] > n[i+1]){
+                int j = i;
+                while(n[j] == n[i]) j--;
+                j++;
+                n[j++] -= 1;
+
+                for(; j < len; j++) n[j] = 9;
+                break;
+            }
+        }
+
+        for(int i = 0; i < len; i++) answer = answer*10+n[i];
+        return answer;
+    }
+};