P23_5
Read Hints\ndiffArray = new [200000+2 ]\nfor every pair(arr[i],arr[len-i-1])\nmin=Min(arr[i],arr[i-len])\nsimllarly max\nNow for all values in diffArray\nadd 2 
Read Hints\ndiffArray = new [200000+2 ]\nfor every pair(arr[i],arr[len-i-1])\nmin=Min(arr[i],arr[i-len])\nsimllarly max\nNow for all values in diffArray\nadd 2 for indexes>max+limit\nadd 2 for indexex<min\nadd 1 to index in betwwenabove\nAnd finally subtratct 1 for index=arr[i]+arr[i-len-1]
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