算法1.3--求n个不同整数中的最大元(MaxElement)

比较次数: N-1

 

#include
#include
#include

#define MAX_LENGTH 100

/*Show usage*/
void usage(char * prog)
{
        printf("%s Usage:\n", prog);
        printf("%s \n", prog);
}

/*Try to find the max one in the list and return it*/
int find_max(int * list, int n)
{
        int i = 1, max;
        max = list[0];
        while(i < n)
        {
                if(max < list[i])
                {
                        max = list[i];
                }
                i ++;
        }
        return max;
}

/*Generate and initialize the list*/
int * generate_list(int count)
{

        int i;
        int * list;
        list = (int *)malloc(count*sizeof(int));
        if(list == NULL)
        {
                perror("malloc");
                return NULL;
        }

        /*Initialize the list with integers less than 100*/
        srandom((unsigned int)time(NULL));
        for (i  = 0; i < count ; i ++)
                list[i] = random()%100;

        return list;
}

int main(int argc, char * argv[])
{
        int length, i;
        int * list = NULL;
        int max;

        /*Deal with the arguments*/
        if(argc != 2)
        {
                usage(argv[0]);
                exit(127);
        }

        length = atoi(argv[1]);
        if(!length || length > MAX_LENGTH)
        {
                usage(argv[0]);
                exit(129);
        }

        list = generate_list(length);
        if(list == NULL)
                exit(128);
        else
        {
                for(i = 0; i < length; i ++)
                        printf("%d ", list[i]);
                printf("\n");
                max = find_max(list, length);
                printf("The max one is: %d\n", max);
        }
        free(list);
        return 1;
}