1057. Stack (30)

来源：互联网发布：mac os x10.7.5下载编辑：程序博客网时间：2024/05/16 18:04

http://blog.csdn.net/x_iya/article/details/8943264
使用树状数组，上面是树状数组的介绍
有一个很大的坑是用cout的时候超时，改成printf就ok了，做题感觉输入输出还是用printf和scanf最快，最稳

#include<iostream>#include<string>#include<vector>#include<algorithm>#pragma warning(disable:4996)using namespace std;int c[100001] = {0};int lowbit(int n){    return n&(-n);}int GetSum(int index){    int sum=0;    while (index != 0)    {        sum += c[index];        index -= lowbit(index);    }    return sum;}void Add(int value, int index){    while (index < 100000)    {        c[index] += value;        index += lowbit(index);    }}int Getmid(int size){    int index = (1 + size) / 2;    int low = 1, high = 100000,mid;    while (low < high)    {        mid = (low + high) / 2;        if (GetSum(mid) < index)            low = mid + 1;        else            high = mid;    }    return low;}int main(){    vector<int> sort_vec;    std::ios::sync_with_stdio(false);//  cout << unitbuf;//  freopen("0.txt", "w", stdout);    vector<int> vec;    int N;    cin >> N;    for (int t = 0;t < N;t++)    {        string str;        cin >> str;        switch (str[1])        {        case 'o':        {            if (vec.empty()) printf("Invalid\n" );            else {                int temp = vec.back();                printf("%d\n", temp);                Add(-1, temp);                vec.pop_back();            }        }        break;        case 'e':        {            if (vec.empty()) printf("Invalid\n");            else printf("%d\n", Getmid(vec.size()));        }        break;        case 'u':        {            int x;            cin >> x;            vec.push_back(x);            Add(1, x);        }        break;        }    }}

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