1057 Stack (30分)

1. 题目

2. 思路

正常思路， 取中使用下标排序 nums[100001] ,nums[index]表示数的个数

3. 注意点

如果每次排序会超时

4. 代码

#include<cstdio>
#include<vector>
#include<string>
#include<stack>

using namespace std;

struct node{
    string command;
    int value;
    node(string command, int value){
        this->command = command;
        this->value = value;
    }
};

int n;

stack<int> s;
vector<node> coms;
int nums[100001];
int index, big, small;

int main(){
    scanf("%d", &n);
    char com[20];
    int value;
    for(int i=0;i<n;i++){
        scanf("%s", com);
        string command(com);
        if(command == "Push"){
            scanf("%d", &value);
        }
        coms.push_back(node(command, value));
    }
    
    for(int i=0;i<n;i++){
        node nod = coms[i];
        if(nod.command == "Push"){
            s.push(nod.value);
            nums[nod.value]++;
            if(s.size() == 1){
                index = nod.value;
                small = 0;
                big = 0;
            }
            if(index != nod.value){
                if(nod.value > index){
                    big++;
                    if(big > small+nums[index]){
                        small += nums[index];
                        for(int j=index+1;;j++){
                            if(nums[j] != 0){
                                big-=nums[j];
                                index = j;
                                break;
                            }
                        }
                    }
                }else if(nod.value < index){
                    small++;
                    if(small >= big+nums[index]){
                        big += nums[index];
                        for(int j=index-1;;j--){
                            if(nums[j] != 0){
                                small-=nums[j];
                                index = j;
                                break;
                            }
                        }
                    }
                }
            }   
        }else if(nod.command == "Pop"){
            if(s.size() == 0){
                printf("Invalid\n");
            }else{
                value = s.top();
                printf("%d\n", value);
                s.pop();
                nums[value]--;
                if(value > index){
                    big--;
                }else if(value < index){
                    small--;
                }
                if(small >= big + nums[index]){
                    big += nums[index];
                    for(int j=index-1;;j--){
                        if(nums[j] != 0){
                            small-=nums[j];
                            index = j;
                            break;
                        }
                    }
                }else if(big > small+nums[index]){
                    small += nums[index];
                    for(int j=index+1;;j++){
                        if(nums[j] != 0){
                            big-=nums[j];
                            index = j;
                            break;
                        }
                    }
                }
            }
        }else{
            if(s.size() == 0){
                printf("Invalid\n");
            }else{
                printf("%d\n", index);  
            }
        }
    }
}

标签：index,1057,nums,int,big,30,value,small,Stack
来源： https://www.cnblogs.com/d-i-p/p/12411443.html