小白，求大神指教时间复杂度

Question

inti,j for(i=0;i＜n;i++)｛ for(j=i;j＜n;j++)｛ /*时间复杂度为O(1)的程序步骤序列*/ ｝ 这个循环时间复杂度为O(n²)为什么不算外循环n次 不应该是(n²/2+n/2)*n

Answer 1

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

Answer 2

同问，不过我感觉这个循环的时间复杂度是n²/2