蓝桥杯算法提高VIP-十进制数转八进制数 （C语言代码）

// 进制为M数值n → 进制N后的结果  (2~16)

#include "stdafx.h"

#include "string.h"

#define M 10

#define N 8

int stoi(char a)

{

if (a >= '0'&&a <= '9')

return a - '0';

else if (a >= 'a'&&a <= 'f')

return a - 'a';

else if (a >= 'A'&&a <= 'F')

return a - 'A';

}

char itos(int a)

{

char x[17] = "0123456789ABCDEF";

return x[a];

}

int aToten(int a,int len,char x[])

{

int i,t=1, sum=0;

for (i = len - 1; i >=0; i--)

{

sum += t * stoi(x[i]);

t *= a;

}

return sum;

}

void Reverse(char* s, int left, int right)

{

if (left >= right)

return;

char t = s[left];

s[left] = s[right];

s[right] = t;

Reverse(s, left + 1, right - 1);

}

char *tenTob(int b,int x)

{

int i=0,k;

static char n[100] = { 0 };

while (x >= b)

{

n[i++] = itos(x%b);

x /= b;

}

n[i] = itos(x);

Reverse(n, 0, i);   //n逆序

return n;

}

int main()

{

//int a, b;

//scanf("%d %d", &a, &b);

char n[100] = { 0 },*a;

gets_s(n, sizeof(n));

puts(tenTob(N,aToten(M,strlen(n),n)));

    return 0;

}