用C中的字符串进行内插搜索

Question

我尝试使用结构中的数据进行插值搜索。例如，我给时间2014-02-13T18：50：00作为输入，并且我希望插值搜索返回温度4.0和嗡嗡声75，但是某些操作不起作用。我认为使用（High-Low）*（In-Low）计算中间值时会出现问题，但我不明白为什么会这样。

---

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



#define SIZE 11
struct metrhseis{
char time[21];
int temp;
int hum;

};
long long int string_To_long(const char  arr[]);
void interpolation_search(struct metrhseis  arr[], char * in);
int main(){

char in[25];
int inI;
int j;
struct  metrhseis s[SIZE];



strcpy(s[0].time, "2014-02-13T06:20:00");
s[0].temp=3.0;
s[0].hum=93;
strcpy(s[1].time, "2014-02-13T13:50:00");
s[1].temp=7.0;
s[1].hum=66;
strcpy(s[2].time, "2014-02-13T06:00:00");
s[2].temp=2;
s[2].hum=91;
strcpy(s[3].time, "2014-02-13T03:00:00");
s[3].temp=3;
s[3].hum=84;
strcpy(s[4].time, "2014-02-13T13:00:00");
s[4].temp=6;
s[4].hum=62;
strcpy(s[5].time, "2014-02-13T18:50:00");
s[5].temp=4.0;
s[5].hum=75;
strcpy(s[6].time, "2014-02-13T13:20:00");
s[6].temp=6.0;
s[6].hum=70;
strcpy(s[7].time, "2014-02-13T15:00:00");
s[7].temp=6;
s[7].hum=56;
strcpy(s[8].time, "2014-02-13T08:50:00");
s[8].temp=4.0;
s[8].hum=87;
strcpy(s[9].time, "2014-02-13T21:50:00");
s[9].temp=4.0;
s[9].hum=75;
strcpy(s[10].time, "2014-02-13T08:00:00");
s[10].temp=3;
s[10].hum=88;

 int i;



  for (i = 0; i < SIZE; i++)
     printf("%s\n%d\n%d\n", s[i].time,  s[i].temp,s[i].hum);

printf("Date:");
scanf("%s",in);
interpolation_search(s, in);


}
 void interpolation_search(struct metrhseis  arr[], char * in){
  long long int High,Low,In;
  long long int mid,low,high;
  low=0;
  high =SIZE - 1 ;
  High = string_To_long(arr[high].time);
  Low = string_To_long(arr[low].time);
  In = string_To_long(in);

  while(low<=high  ){
  High= string_To_long(arr[high].time);
  Low= string_To_long(arr[low].time);

  mid =low+(high-low)/(High-Low)*(In-Low);

  if(strcmp(arr[mid].time,in)>0){
  high=mid-1;
  }
  else if(strcmp(arr[mid].time,in)<0){
  low=mid+1;

 }
 else
 printf("Time: %s Temperatura: %d Hum: %d",arr[mid].time ,arr[mid].temp,arr[mid].hum);
 break;
}

printf("Time: %s Temperatura: %d Hum: %d", in,arr[mid].temp,arr[mid].hum);
}
long long string_To_long(const char arr[]) {
long long int n = 0;
for (int i = 0; arr[i] != '\0'; i++) {
    char c = arr[i];
    if (c >= '0' && c <= '9')
        n = n * 10 + (c - '0');
}
return n;
}

Answer 1

使用有序列表然后计算两次之间的比率，最后显示温度和嗡嗡声

对于2014-02-13T13：40：00获得

时间：20140213134000色温：6.666667嗡嗡声：67.333336

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

struct metrhseis{
    long long int time;
    int temp;
    int hum;

    struct metrhseis *next;
};

long long int string_To_long(const char  arr[]);
void interpolation_search(struct metrhseis  *list, const char * in);
void add_metrhseis(struct metrhseis **list, const char *time, int temp, int hum);
void list_delete(struct metrhseis **list);
void list_print(struct metrhseis *list);

int main(){

    char in[25];
    struct  metrhseis *list = NULL;

    add_metrhseis(&list, "2014-02-13T06:20:00", 3.0, 93);
    add_metrhseis(&list, "2014-02-13T13:50:00", 7.0, 66);
    add_metrhseis(&list, "2014-02-13T06:00:00", 2, 91);
    add_metrhseis(&list, "2014-02-13T03:00:00", 3, 84);
    add_metrhseis(&list, "2014-02-13T13:00:00", 6, 62);
    add_metrhseis(&list, "2014-02-13T18:50:00", 4.0, 75);
    add_metrhseis(&list, "2014-02-13T13:20:00", 6.0, 70);
    add_metrhseis(&list, "2014-02-13T15:00:00", 6, 56);
    add_metrhseis(&list, "2014-02-13T08:50:00", 4.0, 87);
    add_metrhseis(&list, "2014-02-13T21:50:00", 4.0, 75);
    add_metrhseis(&list, "2014-02-13T08:00:00", 3, 88);


    list_print(list);

    printf("Date:");
    scanf("%s",in);
    interpolation_search(list, in);

    list_delete(&list);
}

void list_print(struct metrhseis *m) {
    printf("List\n");
    do {
        printf("%lld:%d,%d\n", m->time, m->temp, m->hum);
        m = m->next;
    } while (m);
}

void list_delete(struct metrhseis **list) {
    struct metrhseis *m = *list;
    if (m->next) {
        list_delete(&m->next);
    }
    free(m);
    *list = NULL;
}
void add_metrhseis(struct metrhseis **list, const char *time, int temp, int hum)
{
    struct metrhseis *current = *list;
    struct metrhseis *m = malloc(sizeof(struct metrhseis));
    m->time = string_To_long(time);
    m->temp = temp;
    m->hum = hum;

    if (*list == NULL || (*list)->time > m->time) {
        m->next = *list;
        *list = m;
        return;
    }
    while (current->next && current->next->time <= m->time) {
        current = current->next;
    }
    m->next = current->next;
    current->next = m;
}

void interpolation_search(struct metrhseis *list, const char * in) {
    long long int time = string_To_long(in);
    float ratio;

    if (time < list->time) {
        printf("Time: %s Temperatura: %d Hum: %d\n", in, list->temp, list->hum);
        return;
    }
    while(list->next && list->next->time < time) {
        list = list->next;
    }
    if (!list->next) {
        printf("Time: %s Temperatura: %d Hum: %d\n", in, list->temp, list->hum);
        return;
    }
    ratio = (float)(time - list->time) / (list->next->time - list->time);
    printf("Time: %s Temperatura: %f Hum: %f\n",
           in,
           list->temp + ratio * (list->next->temp - list->temp),
           list->hum  + ratio * (list->next->hum  - list->hum )
    );
    return;

}
long long string_To_long(const char arr[]) {
    long long int n = 0;
    for (int i = 0; arr[i] != '\0'; i++) {
        char c = arr[i];
        if (c >= '0' && c <= '9')
            n = n * 10 + (c - '0');
    }
    return n;
}