Mei Mei and dress

Mei Mei, being the diva she is, loves to dance. She wants to woo Po and thus decides to buy a dress as colourful as possible. But in order to get the most colourful dress, she has to solve a problem. She has an array of $N$ elements $A_1, A_2, \ldots, A_N$. Each element of the array is between $1$ and $N$(both inclusive). The value at any index is called the intensity of that index. The power o