add solution 121[js]

Author: limbowandering

solution/121.Best Time to Buy and Sell Stock/Solution.js

@@ -0,0 +1,13 @@
+const maxProfit1 = function(prices){
+  let min = prices[0];
+  let profit = 0;
+  for(let i = 0; i < prices.length; i++){
+    if(prices[i] < min){
+      min = prices[i];
+    }
+    if(profit < (prices[i] - min)){
+      profit = prices[i] - min;
+    }
+  }
+  return profit;
+}