#include<stdio.h>

#include<stdlib.h>

#include<string.h>

#define MAXINT 0x7fffffff

#define MININT 0X80000000

//字符串中第一个只出现一次的字符

char firstSingle(char *str)

{

	int a[255];

	memset(a, 0, 255 * sizeof(int));

	char *p = str;

	while (*p != '\0'){

		++a[*p];

		++p;

	}

	p = str;

	while (*p != '\0'){

		if (a[*p] == 1) return *p;

		++p;

	}

	return '\0';

}

//josephus问题 f(n,m)=(f(n-1,m)+m)%n,迭代求解最后一个数的原始数

int joseph(int n, int m)

{

	int fn = 0;

	for (int i = 2; i <= n; ++i)

		fn = (fn + m) % i;

	return fn;

}

//最大子数组和

int maxSubArraySum(int *a, int n, int &b, int &e)

{

	int p, sum, maxSum;

	p = sum = 0;

	maxSum = MININT;

	for (int i = 0; i < n; ++i){

		if (sum < 0){

			sum = a[i];

			p = i;

		}

		else sum += a[i];

		if (sum > maxSum){

			maxSum = sum;

			b = p;

			e = i;

		}

	}

	return maxSum;

}

int main()

{

	char str[] = "abaccdeff";

	printf("%c\n", firstSingle(str));

	printf("%d\n", joseph(5, 3));

	int a[] = { 13, -3, -25, 20, -3, -16, -23, 18, 20, -7, 12, -5, -22, 15, -4, 7 };

	int len, b, e;

	len = maxSubArraySum(a, 16, b, e);

	printf("the maxSubArray is :\n");

	for (int i = b; i <= e; ++i)

		printf("%d\t", a[i]);

	printf("\nthe maxSubArraySum is : %d\n", len);

}