计算由a,b,c组成一个数有多少种组合

#define _CRT_SECURE_NO_WARNINGS
#include<stdio.h>
#include<stdlib.h>
void check_count();
void combineNum(int x, int y, int z,int num);
int main() {
    
    combineNum(5,2,1,100);
    return 0;
}

void combineNum(int x,int y,int z,int num) {
    
    int i = 0, j = 0, k = 0,n=0;
    for (int i = 0; i*x <= num; i++) {
        
        for (int j = 0; j*y <= num - i*x;j++) {
            for (int k = 0; k*z <= num - i*x - j*y; k++) {
                if ((i*x + j*y + k*z) == num) {
                    printf("组合为：%d,%d,%d\n", i, j, k);
                    n++;
                }
            }
            
        }
    }
    if (n!=0) {
        printf("总计%d", n);
    }
    else {
        printf("无", n);
    }
    

}