in c please

I have a sorted array of N lower case names. I think that someone might be listed too many times. I want a function that will tell me if some given person is listed at least k times (some given integer). The function should return 1 is the person is contained at least k time, and 0 otherwise. Your program must take O(log(N)) comparisons. You must use the following prototype. int tooMany (int n, char ** arr, char * target, int k)