５人の学生を 身長・体重で ソート (関数ポインタ)
明解Ｃ言語 入門編 > 12. 構造体 >
５人の学生を 身長・体重で ソート (関数ポインタ)
C
#include <stdio.h>
#include <string.h>#define NINSU 5
typedef struct
{
char name[20];
int height;
float weight;
} gstudent;typedef
int (*compare)(gstudent*, gstudent*);int compare_height(gstudent* x, gstudent* y)
{
if (x->height > y->height) return 1;
if (x->height < y->height) return -1;
return 0;
}
int compare_weight(gstudent* x, gstudent* y)
{
if (x->weight > y->weight) return 1;
if (x->weight < y->weight) return -1;
return 0;
}void swap(gstudent* x, gstudent* y)
{
gstudent tmp = *x;
*x = *y;
*y = tmp;
}void sort(gstudent data[], int n, compare comp)
{
int k = n - 1;
while (k >= 0)
{
int i, j;
for (i = 1, j = -1; i <= k; i++)
{
if (comp(&data[i - 1], &data[i]) > 0)
{
j = i - 1;
swap(&data[i], &data[j]);
}
}
k = j;
}
}int main(int argc, char* argv[])
{
int i;
gstudent data[] =
{
"Sato", 178, 61.0,
"Sanaka", 175, 60.5,
"Takao", 173, 80.0,
"Mike", 165, 72.0,
"Masaki", 179, 77.5
};puts("ソート前：");
for (i = 0; i < NINSU; i++)
printf("%2d:%-8s%4d%6.1f\n", i + 1, data[i].name, data[i].height, data[i].weight);
puts("");/* 身長でソート */
sort(data, NINSU, &compare_height);puts("身長でソート後：");
for (i = 0; i < NINSU; i++)
printf("%2d:%-8s%4d%6.1f\n", i + 1, data[i].name, data[i].height, data[i].weight);
puts("");/* 体重でソート */
sort(data, NINSU, &compare_weight);puts("体重でソート後：");
for (i = 0; i < NINSU; i++)
printf("%2d:%-8s%4d%6.1f\n", i + 1, data[i].name, data[i].height, data[i].weight);return 0;
}
実行結果
T:\>lesson097\project1.exe
ソート前：
1:Sato 178 61.0
2:Sanaka 175 60.5
3:Takao 173 80.0
4:Mike 165 72.0
5:Masaki 179 77.5身長でソート後：
1:Mike 165 72.0
2:Takao 173 80.0
3:Sanaka 175 60.5
4:Sato 178 61.0
5:Masaki 179 77.5体重でソート後：
1:Sanaka 175 60.5
2:Sato 178 61.0
3:Mike 165 72.0
4:Masaki 179 77.5
5:Takao 173 80.0
