a2b

解码后：aab

​
#include<iostream>
using namespace std;
typedef struct Node {
	char data;
	int size;
	Node* next;
}Node,*Linklist;
char* scan(char str[],int size) {
	int i = 0;
	Linklist head = new Node;
	Linklist rear = head;
	while (i<size-1) {
		Linklist node = new Node;
		if (str[i+1] > '1' && str[i+1] <= '9') {
			node->data = str[i];
			node->size = str[i + 1] - '0';
			rear->next = node;
			rear = node;
			i += 2;
		}
		else {
			node->data = str[i];
			node->size = 1;
			rear->next = node;
			rear = node;
			i += 1;
		}
	}if (i<size && (str[i] <'1' || str[i] > '9')) {
		Linklist node = new Node;
		node->data = str[i];
		node->size = 1;
		rear->next = node;
		rear = node;
		i += 1;
	}
	rear->next = nullptr;
	Linklist p = head->next;
	char* str1 = new char[i+1];
	int k = 0;
	while (p != nullptr) {
		for (int j = p->size; j > 0;j--) {
			str1[k] = p->data;
			k++;
		}
		p = p->next;
	}
	str1[k] = '\0';
	return str1;
}
int main() {
	char str[40];
	int i = 0;
	do {
		str[i] = getchar();
		i++;
	} while (str[i-1] != '\n');
	char* str1 = scan(str,i-1);
	cout <<str1;
	return 0;
}

​

参考

#include<iostream>
#include<cstring>
using namespace std;
int main(){
    char s[101];
    cin>>s;
    int len;
    len = strlen(s);
    for(int i = 0;i<len;i++){
        if(s[i+1]>'1' && s[i+1]<='9' ){
            for(char j = '1';j<=s[i+1];j++){
                cout<<s[i];
            }
            i++;
        }else{
            cout<<s[i];
        }
    }
    return 0;
}