HDU-6186(CS Course)

对于and和or运算分别记录一个前缀运算和后缀运算, 去掉k位置值得运算结果就为前缀和后缀的运算结果

#include 

using namespace std;

const int MAXN = 1e5 + 5;

int a[MAXN], andl[MAXN], andr[MAXN], orl[MAXN], orr[MAXN], xora;

int main(){
    int n, p;
    while(cin >> n >> p){
        andl[0] = andr[n+1] = ~0;
        orl[0] = orr[n+1] = xora = 0;
        for(int i = 1; i <= n; ++i) cin >> a[i];
        for(int i = 1; i <= n; ++i){
            andl[i] = andl[i-1]&a[i];
            orl[i] = orl[i-1]|a[i];
            xora ^= a[i];
        }
        for(int i = n; i >= 1; --i){
            andr[i] = andr[i+1]&a[i];
            orr[i] = orr[i+1]|a[i];
        }
        for(int i = 0; i < p; ++i){
            int k;
            cin >> k;
            cout << (andl[k-1] & andr[k+1]) <<" " << (orl[k-1] | orr[k+1]) << " " << (xora ^ a[k]) << endl;
        }
    }
    return 0;
}