線性表順序儲存-練習題3-逆置順序表
阿新 • • 發佈:2019-03-02
題目:
以順序表作儲存結構實現線性表,實現就地逆置演算法,即在原表的儲存空間將線性表(a1, a2, ..., an)逆置為(an, ... , a2, a1).
思路:
- 需要考慮的線性表個數的奇/偶數情況,奇/偶數情況不同,置換的步伐長度不同
- 設定一箇中轉數,當做數置換時做中轉儲存
程式碼:
#include <stdio.h>
#include <stdlib.h>
#define MAXSIZE 101
typedef struct {
int r[MAXSIZE];
int length;
} SqList;
void inverseElement(SqList *L);
void print(SqList L);
int main(int argc, char *argv[]) {
SqList list;
int i;
list.length = 9;
for (i = 1; i <= list.length; i++) {
list.r[i] = i * 3;
}
printf("初始順序表:\n");
print(list);
printf("\n");
inverseElement(&list);
printf("置換後的順序表:\n");
print(list);
return 0;
}
/**
* 逆置順序表
*/
void inverseElement(SqList *L) {
int middle = 0, k = -1, i;
if (L->length % 2 == 0) {
for (i = L->length / 2; i > 0; i--) {
k += 2;
middle = L->r[i];
L->r[i] = L->r[i + k];
L->r[i + k] = middle;
}
} else {
k = 0;
for (i = L->length / 2; i > 0; i--) {
k += 2;
middle = L->r[i];
L->r[i] = L->r[i + k];
L->r[i + k] = middle;
}
}
}
void print(SqList L) {
for (int i = 1; i <= L.length; i++) {
printf("%d\t", L.r[i]);
}
}