POJ2503 Babelfish(二分)

题目链接。

分析；

主要是学着用一下bsearch。

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

struct Entry{
    char english[15], foreign[15];
}entrys[100010];

int cmp(const void *a, const void *b){
    return strcmp((*(struct Entry *)a).foreign, (*(struct Entry *)b).foreign);
}

int b_cmp(const void *a, const void *b){
    return strcmp((char *)a, (*(struct Entry *)b).foreign);
}

int main(){
    char s[30];
    int top=0;
    struct Entry *p;

    while(gets(s)){
        if(s[0] == '\0') break;
        sscanf(s, "%s %s", entrys[top].english, entrys[top].foreign);
        top++;
    }

    qsort(entrys, top, sizeof(entrys[0]), cmp);

    while(scanf("%s", s) == 1){
        p = (struct Entry *)bsearch(s, entrys, top, sizeof(entrys[0]), b_cmp);
        if(p == NULL){
            printf("eh\n");
        }
        else printf("%s\n", p->english);
    }


    return 0;
}

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

struct Entry{
    char english[15], foreign[15];
}entrys[100010];

int cmp(const void *a, const void *b){
    return strcmp((*(struct Entry *)a).foreign, (*(struct Entry *)b).foreign);
}

int b_cmp(const void *a, const void *b){
    return strcmp((char *)a, (*(struct Entry *)b).foreign);
}

int main(){
    char s[30];
    int top=0;
    struct Entry *p;

    while(gets(s)){
        if(s[0] == '\0') break;
        sscanf(s, "%s %s", entrys[top].english, entrys[top].foreign);
        top++;
    }

    qsort(entrys, top, sizeof(entrys[0]), cmp);

    while(scanf("%s", s) == 1){
        p = (struct Entry *)bsearch(s, entrys, top, sizeof(entrys[0]), b_cmp);
        if(p == NULL){
            printf("eh\n");
        }
        else printf("%s\n", p->english);
    }


    return 0;
}