代码

#include <sys/auxv.h>
#include <stdint.h>
struct DuckInfo {
  uint64_t abi_version; const char *stdin_ptr; uint64_t stdin_size;
  char *stdout_ptr; uint64_t stdout_limit; uint64_t stdout_size;
  char *stderr_ptr; uint64_t stderr_limit; uint64_t stderr_size;
  const char *IB_ptr; uint64_t IB_limit; char *OB_ptr; uint64_t OB_limit;
  uint64_t tsc_frequency;
} __attribute__((packed));
int main(){
  DuckInfo* di=(DuckInfo*)getauxval(0x6b637564ull);
  volatile unsigned long long acc=0;
  for (unsigned long long i=0;i<100000000;i++) acc+=i;
  char* o=di->stdout_ptr; char b[24]; int t=0; unsigned long long v=acc;
  do{b[t++]='0'+(v%10);v/=10;}while(v); while(t)*o++=b[--t]; *o++='\n';
  di->stdout_size=(unsigned long long)(o-di->stdout_ptr);
  asm volatile("mov $60, %%eax; xor %%edi, %%edi; syscall" ::: "rax","rdi","rcx","r11","memory");
  __builtin_unreachable();
}

评测结果