目录
1.双向循环链表排序
冒泡排序
插入排序还没写好，加上老师讲了。有空写了再把代码贴上。
用个end指针表示排序的范围，从1-n，到1-n-1，……直到1-1。
然后用两个指针指向相邻的结点进行操作。注意结点更改链接时的操作顺序。
#include<bits/stdc++.h>
using namespace std;
struct node{
int data;
node* pre;
node* nxt;
};
int len = 0;
node* head = NULL;
node* tail = NULL;
void create(){
node *p;
int x;
while(cin >> x , x != 0 ){
len++;
p = new node;
p->data = x;
if(head == NULL){
head = p;
tail = p;
}
else{
tail->nxt = p;
p->pre = tail;
tail = p;
}
}
tail->nxt = head;
head->pre = tail;
}
void print();
void Bubble_Sort(){
node *cur,*next,*end;
end = head;
do{
for(cur = head, next = cur->nxt; next != end ; cur = cur->nxt , next = next->nxt){
if(cur->data > next ->data){
cur->pre->nxt = next;
if(cur == head) head = next,end = next;
next->nxt->pre = cur;
next->pre = cur->pre;
cur->nxt = next->nxt;
cur->pre = next;
next->nxt = cur;
node* tmp = cur;
cur = next;
next = tmp;
}
// print();
}
end = cur;
}while(head != end);
}
void print(){
node* p = head;
do{
cout << p->data << " ";
p = p->nxt;
}while(p != head);
cout << endl;
}
int main(){
create();
Bubble_Sort();
print();
}
/*
test: 1 7 8 9 10 2 3 5 4 6 0
2 1 1 1 1 3 3 3 4 4 1 0
9 8 7 6 5 4 3 2 1 0
3213 231 411 242 8934 3218 32153 132 0
1 2 3 4 5 6 7 8 9 10 0
*/
插入排序
没写。
2.字符串镜像
我把函数放结构体里面了。等我有空写个链表栈。
#include<bits/stdc++.h>
using namespace std;
char s[1001];
struct stk{
int size = 0;
char data[1001];
void pop(){
size--;
}
char top(){
return data[size];
}
void push(char x){
size++;
data[size] = x;
}
};
int main(){
cin >> s;
stk a;
int len = strlen(s) , i ;
for(i = 0 ; i < len ; i++ ){
if(s[i] == '&') break;
a.push(s[i]);
}
i++;
int ans = a.size ;
for(; i < len-1 ; i++){
if(s[i] == a.top()) a.pop();
else {
cout << "no" ;
return 0 ;
}
}
cout << ans <<endl;
}
3.表达式求值
百度一下运算符的优先级，然后用个数组映射。减和除的时候注意一下顺序。
小数点前后分别用整形和浮点型的变量来保存，因为两者的运算逻辑不同，然后相加即可。
利用c++泛型编程的特性，设计一个栈模板就可以存字符和数字了。
#include<cstdio>
template <typename T>
struct stack{
int size = 0;
T data[1001];
void pop(){
size--;
}
T top(){
return data[size];
}
void push(T x){
size++;
data[size] = x;
}
};
int priority[128][128];
void init_priority(){
priority['+']['+'] = 1;
priority['-']['+'] = 1;
priority['*']['+'] = 1;
priority['/']['+'] = 1;
priority['(']['+'] = 0;
priority[')']['+'] = 1;
priority['#']['+'] = 0;
priority['+']['-'] = 1;
priority['-']['-'] = 1;
priority['*']['-'] = 1;
priority['/']['-'] = 1;
priority['(']['-'] = 0;
priority[')']['-'] = 1;
priority['#']['-'] = 0;
priority['+']['*'] = 0;
priority['-']['*'] = 0;
priority['*']['*'] = 1;
priority['/']['*'] = 1;
priority['(']['*'] = 0;
priority[')']['*'] = 1;
priority['#']['*'] = 0;
priority['+']['/'] = 0;
priority['-']['/'] = 0;
priority['*']['/'] = 1;
priority['/']['/'] = 1;
priority['(']['/'] = 0;
priority[')']['/'] = 1;
priority['#']['/'] = 0;
priority['+']['('] = 0;
priority['-']['('] = 0;
priority['*']['('] = 0;
priority['/']['('] = 0;
priority['(']['('] = 0;
// priority[')']['('] = 1;
priority['#']['('] = 0;
priority['+'][')'] = 1;
priority['-'][')'] = 1;
priority['*'][')'] = 1;
priority['/'][')'] = 1;
priority['('][')'] = -1;
priority[')'][')'] = 1;
// priority['#'][')'] = 1;
priority['+']['#'] = 1;
priority['-']['#'] = 1;
priority['*']['#'] = 1;
priority['/']['#'] = 1;
// priority['(']['#'] = 0;
priority[')']['#'] = 1;
priority['#']['#'] = -1;
}
double calc(double x, char op ,double y){
if(op == '+')
return x + y;
if(op == '-')
return y - x;
if(op == '*')
return x * y;
if(op == '/')
return y / x;
}
int main(){
stack<double> num;
stack<char> op;
init_priority();
char Input[100];
op.push('#');
scanf("%s",Input);
char c = Input[0]; int pos = 0;
while(c != '#' || op.top() != '#'){
// cout << c<< endl<< num.top()<<endl;
int Int = 0; double Double = 0;
if(c >= '0' && c <= '9') {
while(c >= '0' && c <= '9'){
Int = Int*10 + (c - '0');
// cout << Int << endl;
c = Input[++pos];
}
if( c == '.'){
int y = 10;
c = Input[++pos];
while(c >= '0' && c <= '9'){
Double += (c - '0')/(double)y;
y *= 10;
c = Input[++pos];
}
}
// cout << Int + Double<< " " << endl;
num.push(Int + Double);
}
else {
// cout << op.top() << " " << c << " ";
// cout << priority[op.top()][c] <<endl;
if(priority[op.top()][c] == -1){
op.pop();
c = Input[++pos];
}
else if(priority[op.top()][c]){
// cout << "op" <<endl;
char opr = op.top();op.pop();
double x = num.top();num.pop();
double y = num.top();num.pop();
num.push(calc(x,opr,y));
// cout << num.top()<<endl;
}
else {
op.push(c);
c = Input[++pos];
}
}
}
printf("%.2f", num.top());
return 0;
}
4.学生信息管理
没写。
