使int n依次和2的次方进行与操作(&)，得知每个位是0还是1，并且写入字符数组，返回写有数字二进制信息的字符指针。
#include <stdio.h>#include <stdlib.h>char *toBinary(int num){ char *binary = (char *)malloc(sizeof(char) * 33); int flag = 1; int i; for (i = 31; i >= 0; i--) { if (num & flag) { binary[i] = '1'; } else { binary[i] = '0'; } flag<<=1; } binary[32] = ' '; return binary;}int main(){ char *tmp; for (int i = -16; i <= 16; i++) { tmp = toBinary(i); printf("%d:t%sn", i, tmp); free(tmp); tmp = NULL; } return 0;} #include<stdio.h>#include<stdlib.h>char* ToBin(int num){int flag=1;char* result=(char*)malloc(sizeof(char)*33);int i;for(int i=31;i>=0;i--){if(num & flag){result[i]='1';}else{result[i]='0';}flag<<=1;}result[32]=' ';return result;}int main(){int a1=28;int a2=-28;char* a;int i=0;printf("%s","I am CDQ!n ");a = ToBin(a1); //a= ToBin(a2);printf("a1:");for(int i=0;i<33;i++){printf("%c",a[i]);}printf("%c",'n');free(a);a = NULL;return 0;} I am CDQ!a1:00000000000000000000000000011100I am CDQ!a2:11111111111111111111111111100100参考链接：https://www.cnblogs.com/noonjuan/p/12343042.html