c语言自由组合拆分简单

如何用两个for直接解题
https://ask.csdn.net/questions/7542438?answer=7542438&spm=1005.2026.3001.5703

#include <stdio.h>
int main(void)
{
        int sum,low,up;
        while(1)
        {
                fputs("输入一个整数：",stdout);
                scanf("%d",&sum);
                for(low=0;low<=sum/2;low++)
                        for(up=sum/2;up<=sum;up++)
                                if((low+up)==sum)
                                        printf("%d+%d=%d\n",low,up,sum);
        }
        return 0;
}