sqrt() 函数中 c 中的 domain_error

Question

#include<stdio.h>
#include<string.h>
#include<stdlib.h>
#include<conio.h>

typedef struct freqm {
  int dfreq[100];
  char word[10];
} freqm;

freqm fm[10];
int mat[10][10];
float sim[10][10];
int dsize[20];

int search(freqm fm[10], int t_cnt, char term[10]);
void print_cnt(freqm fm[10], int d_cnt, int t_cnt);
int read_files(int d_cnt);
void build_sim(int d_cnt, int t_cnt);
void print(int d_cnt);

void main() {
  int d_cnt, c_cnt, t_cnt;
  clrscr();
  printf("\n\tenter no of documents");
  scanf("%d", &d_cnt);
  t_cnt = read_files(d_cnt);
  print_cnt(fm, d_cnt, t_cnt);
  build_sim(d_cnt, t_cnt);
  print(d_cnt);
  getch();
}

int read_files(int d_cnt) {
  int flag = 0, i, j, t_cnt = 0, count;
  char str[10], str1[10], input[10], term[10];
  FILE *fp;
  printf("\nenter ip prefix");
  scanf("%s", input);
  for (i = 1; i <= d_cnt; i++) {
    strcpy(str1, input);
    sprintf(str, "%d", i);
    strcat(str1, str);
    strcat(str1, ".txt");
    fp = fopen(str1, "r");
    while (fscanf(fp, "%s %d", term, &count) != EOF) {
      flag = 0;
      //fflush(stdin);

      dsize[i] = dsize[i] + count;
      if (i > 1)
        flag = search(fm, t_cnt, term);
      if (i == 1 || flag == -1) {
        fm[t_cnt].dfreq[i] = count;
        strcpy(fm[t_cnt].word, term);
        t_cnt++;
      } else
        fm[flag].dfreq[i] = count;
    }
  }
  return t_cnt;
}

void print_cnt(freqm fm[10], int d_cnt, int t_cnt) {
  int i, j;
  for (i = 0; i < t_cnt; i++) {
    printf("\n%s", fm[i].word);
    for (j = 1; j <= d_cnt; j++)
      printf("\t%d", fm[i].dfreq[j]);
  }
}

int search(freqm fm[10], int t_cnt, char term[10]) {
  int i;
  for (i = 0; i < t_cnt; i++)
    if (strcmp(fm[i].word, term) == 0)
      return i;
  return -1;
}

void build_sim(int d_cnt, int t_cnt) {
  int i, j, sum = 0, k;
  float res = 0, res1, temp, temp1;
  for (i = 1; i <= d_cnt; i++) {
    temp = dsize[i];
    for (j = i + 1; j <= d_cnt; j++) {
      sum = 0;
      temp1 = dsize[j];
      for (k = 0; k < t_cnt; k++)
        sum = sum + min(fm[k].dfreq[i], fm[k].dfreq[j]);
      printf("sum=== %d", sum);
      printf("t1 %d %d", temp, temp1);
      //res1=(float)(sqrt(temp)*sqrt(temp1));
      printf("\n%f", res1);
      res = sum / sqrt(temp1) * sqrt(temp);
      sim[i][j] = res;
    }
  }
}

void print(int d_cnt) {
  int i, j;
  for (i = 1; i <= d_cnt; i++) {
    printf("\n");
    for (j = 1; j <= d_cnt; j++)
      printf("\t%f", sim[i][j]);
  }
}



//input1.txt
T1 0
T2 3
T3 5
T4 1
//input2.txt
T1 5
T2 0
T3 0
T4 1

I was writing code for single pass clustering algorithm. But in function build_sim I get domain_error even though values of temp and temp1 are positive ie 9 and 6. How to resolve this problem?

I'm using turboc. Is it the problem related to turbo c?

Answer 1

Major issue:

1) Wrong format specifiers

float res = 0, res1, temp, temp1;
...
// printf("t1 %d %d", temp, temp1);
printf("t1 %f %f", temp, temp1);

2) Missing #include <math.h> for sqrt() . This likely explains the problem as without a prototype, sqrt assumed to return int . This results in undefined behavior.

Number of minor problems:

3) poor main() declaration

// void main()
int main(void)

4) c_cnt never used. j never used in read_files()

5) Also not certain if your include files contain min() . Double check that.