代码

extern "C" char **environ;
extern "C" { int printf(const char*,...); unsigned long strlen(const char*); void* memcpy(void*,const void*,unsigned long);
 char* strcpy(char*,const char*); void* malloc(unsigned long); void free(void*); char* getenv(const char*);
 int puts(const char*); void* memset(void*,int,unsigned long); int snprintf(char*,unsigned long,const char*,...);
 int strcmp(const char*,const char*); void qsort(void*,unsigned long,unsigned long,int(*)(const void*,const void*)); }
static inline void raw_exit(int c){ register long rax __asm__("rax")=60; register long rdi __asm__("rdi")=c; __asm__ volatile("syscall"::"a"(rax),"D"(rdi):"rcx","r11","memory"); }
extern "C" int __libc_start_main(int (*main)(int,char**,char**), int argc, char **argv){
  environ = argv+argc+1;
  main(argc, argv, argv+argc+1);
  raw_exit(0);
  return 0;
}

int main(){ int a[8]={5,3,1,7,2,8,6,4}; qsort(a,8,4,0); volatile int c=a[0]; if(c==99) raw_exit(1);
 return 0; }

评测结果