Create Day 19 Online Stock Span.cpp

Author: tusharjaiswal123

Day 19 Online Stock Span.cpp

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+PROBLEM:
+
+
+Write a class StockSpanner which collects daily price quotes for some stock, and returns the span of that stock's price for the
+current day.
+The span of the stock's price today is defined as the maximum number of consecutive days (starting from today and going backwards)
+for which the price of the stock was less than or equal to today's price.
+For example, if the price of a stock over the next 7 days were [100, 80, 60, 70, 60, 75, 85], then the stock spans would
+be [1, 1, 1, 2, 1, 4, 6].
+
+ 
+Example 1:
+Input: ["StockSpanner","next","next","next","next","next","next","next"], [[],[100],[80],[60],[70],[60],[75],[85]]
+Output: [null,1,1,1,2,1,4,6]
+Explanation: 
+First, S = StockSpanner() is initialized.  Then:
+S.next(100) is called and returns 1,
+S.next(80) is called and returns 1,
+S.next(60) is called and returns 1,
+S.next(70) is called and returns 2,
+S.next(60) is called and returns 1,
+S.next(75) is called and returns 4,
+S.next(85) is called and returns 6.
+
+Note that (for example) S.next(75) returned 4, because the last 4 prices
+(including today's price of 75) were less than or equal to today's price.
+ 
+
+Note:
+
+1.Calls to StockSpanner.next(int price) will have 1 <= price <= 10^5.
+2.There will be at most 10000 calls to StockSpanner.next per test case.
+3.There will be at most 150000 calls to StockSpanner.next across all test cases.
+4.The total time limit for this problem has been reduced by 75% for C++, and 50% for all other languages.
+
+
+
+
+
+SOLUTION:
+
+
+
+class StockSpanner {
+private:
+    
+    stack<pair<int,int>> s;
+    int c;
+    
+public:
+    StockSpanner() {
+      c=0;  
+    }
+    
+    int next(int price) {
+        
+        while(!s.empty() && price>=s.top().second)
+        {
+            s.pop();
+        }
+        
+        int ans;
+        
+        if(s.empty())
+            ans = c + 1;
+        else
+            ans = c - s.top().first;
+        
+        s.push({c,price});
+        c++;
+        
+        return ans;
+    }
+};
+
+/**
+ * Your StockSpanner object will be instantiated and called as such:
+ * StockSpanner* obj = new StockSpanner();
+ * int param_1 = obj->next(price);
+ */