n进制转m进制

/*
计算字符串中子串出现的次数。
*/
#include<stdio.h>
#include<math.h>
#include<malloc.h>
#include<string.h>
#include<stdlib.h>
/*
10进制转8进制
*/
int convertDecimalToOctal(int num10){
    int num8=0,i=1;
    while(num10!=0){
        num8+=(num10%8)*i;
        i*=10;
        num10/=8;
    }
    return num8;
}
/*
8进制转10进制
*/
int convertOctalToDecimal(int num8){
    int num10=0,i=1;
    while(num8!=0){
        num10+=(num8%10)*i;
        i*=8;
        num8/=10;
    }
    return num10;
}
/*
2进制转8进制
*/
int convertBinarytoOctal(long long num2){
    int num8 = 0,num10=0,i=1;
    while(num2!=0){
        num10+=(num2%10)*i;
        i*=2;
        num2/=10;
    }
    i=1;
    while(num10!=0){
        num8+=(num10%8)*i;
        i*=10;
        num10/=8;
    }
    return num8;
}
/*
8进制转2进制
*/
int convertOctaltoBinary(int num8){
    int num10=0,i=1;
    long long num2=0;
    while(num8!=0){
        num10+=(num8%10)*i;
        i*=8;
        num8/=10;
    }
    i=1;
    while(num10!=0){
        num2+=(num10%2)*i;
        i*=10;
        num10/=2;
    }
    return num2;
}

main()
{
    printf("%d
",convertDecimalToOctal(78));
    printf("%d
",convertOctalToDecimal(116));
    printf("%d
",convertBinarytoOctal(101001));
    printf("%d
",convertOctaltoBinary(51));
}