sample.cpp

#include <string.h>
#include <string>
#include <iostream>
#include <sstream>
#include <cstdio>
#include <openssl/sha.h>

void calSHA256(char* inp,char out_buff[65]){
  unsigned char hash[SHA256_DIGEST_LENGTH];
  SHA256_CTX sha256;
  SHA256_Init(&sha256);
  SHA256_Update(&sha256, inp, strlen(inp));
  SHA256_Final(hash, &sha256);

  //char buffx[65];
  for(int i = 0; i < SHA256_DIGEST_LENGTH; i++)
  {
    sprintf(out_buff + (i * 2), "%02x", hash[i]);
  }
  out_buff[65] = 0;
  //memcpy(out_buff,buffx,65);
}

void itos(int n,char *buffer){
int i = 0;

bool isNeg = n<0;

unsigned int n1 = isNeg ? -n : n;

while(n1!=0)
{
    buffer[i++] = n1%10+'0';
    n1=n1/10;
}

if(isNeg)
    buffer[i++] = '-';

buffer[i] = '\0';

for(int t = 0; t < i/2; t++)
{
    buffer[t] ^= buffer[i-t-1];
    buffer[i-t-1] ^= buffer[t];
    buffer[t] ^= buffer[i-t-1];
}

if(n == 0)
{
    buffer[0] = '0';
    buffer[1] = '\0';
}
}

long stoi(const char *s)
{
    long i;
    i = 0;
    while(*s >= '0' && *s <= '9')
    {
        i = i * 10 + (*s - '0');
        s++;
    }
    return i;
}

using namespace std;

int main(int argc,char** argv){
  if(argc < 2)
    return 1;

  int c = stoi(argv[1]);
  if(c<0)
    return 1;
printf("%d\n",c);
  char  buff[65];
  for(int i=0;i<c;i++){
    itos(i,buff);
    calSHA256(buff,buff);
    printf("%s\n",buff);
  }
}