Time: 184 ms (53.80%), Space: 49.9 MB (40.78%) - LeetHub

Author: JanaSabuj

number-of-matching-subsequences/number-of-matching-subsequences.cpp

@@ -0,0 +1,32 @@
+class Solution {
+public:
+    int numMatchingSubseq(string str, vector<string>& words) {
+        vector<vector<int>> vec(26);
+        int n = str.size();
+        
+        for(int i = 0; i < n; i++){
+            vec[str[i] - 'a'].push_back(i);
+        }
+        
+        int cnt = 0;
+        
+        for(auto w: words){
+            int curr_idx = -1;
+            bool flag = true;
+            
+            for(auto c: w){
+                int idx = upper_bound(vec[c - 'a'].begin(), vec[c - 'a'].end(), curr_idx) - vec[c - 'a'].begin();
+                if(idx >= (int)vec[c - 'a'].size()){
+                    flag = false;
+                    break;
+                }
+                curr_idx = vec[c - 'a'][idx];
+            }
+            
+            if(flag)
+                cnt++;
+        }
+        
+        return cnt;
+    }
+};