令G為一個圖,且f為一個函數,使得G中的每一個頂點都對應至一個正整數。同時定義 ,其中H為G的子圖。如果對於每一個正整數 ,皆存在G的一個連通子圖H,使得f (H) = k,則我們稱f為G的一個〝IC-著色〞。很顯然,對於任意的連通圖G至少存在一個〝IC-著色〞。圖G的〝IC-指數〞定義為M (G) = max { f (G) : f為圖G的一個IC-著色}。如果f是G的一個IC-著色,使得f (G)=M (G),則我們稱f為G的一個〝極大IC-著色〞。在[7]中,E. Salehi等人證明 。在這一篇論文中,我們找出 的IC-指數的上界與下界, 。
Let G be a graph and let f be a function which maps V(G) into the set of positive integers. We define for each subgraph H of G. We say f to be an IC-coloring of G if for any integer there is a connected subgraph H of G such that f (H)= k. Clearly, any connected graph G admits an IC-coloring. The IC-index of a graph G, denoted by M (G), is defined to be M (G) = max { f (G) : f is an IC- coloring of G }. If f is an IC-coloring of G such that f (G) = M (G), then we say that f is a maximum IC-coloring of G. In [7], E. Salehi et.al. proved that . In this thesis, we find that .