hdu 5741(二分)

用前缀和, 搞出上边界和下边界.询问的时候二分

#include <bits/stdc++.h>

using namespace std;

#define LL long long
#define pii pair<int, int>
#define MP make_pair
#define ls i << 1
#define rs ls | 1
#define md (ll + rr >> 1)
#define inf 0x3f3f3f3f
#define mod 1000000007
#define N 1000020
#define M 500020

int n, m, f0[N], f1[N], x[N];
pii low[N], upp[N];
int c1, c2;
void prepare(){
    for(int i = 1; i <= n; ++i){
        if(i & 1) f0[i] = f0[i-1] + x[i], f1[i] = f1[i-1];
        else f0[i] = f0[i-1], f1[i] = f1[i-1] + x[i];
    }
    int t1 = 0, t2 = 0;
    for(int i = 1; i <= n; ++i){
        for(int j = i; j <= n; ++j){
            if((i & 1) && (j & 1))
                low[t1++] = MP(f0[j] - f0[i-1], f1[j] - f1[i-1]);
            if(!(i & 1) && !(j & 1))
                upp[t2++] = MP(f0[j] - f0[i-1], f1[j] - f1[i-1]);
        }
    }
    sort(low, low + t1);
    sort(upp, upp + t2);
    c1 = 0, c2 = 0;
    for(int i = 0; i < t1; ++i){
        if(i > 0 && low[i].first == low[c1-1].first && low[i].second >= low[c1-1].second) continue;
        while(c1 > 0 && low[i].second <= low[c1-1].second) c1--;
        low[c1++] = low[i];
    }
    for(int i = 0; i < t2; ++i){
        if(i > 0 && upp[i].first == upp[c2-1].first && upp[i].second <= upp[c2-1].second) continue;
        if(!c2 || c2 > 0 && upp[i].second > upp[c2-1].second) 
            upp[c2++] = upp[i];
    }
}
int main(){
    int cas;
    scanf("%d", &cas);
    while(cas--){
        scanf("%d%d", &n, &m);
        for(int i = 1; i <= n; ++i)
            scanf("%d", &x[i]);
        prepare();
        int a, b;
        while(m--){
            scanf("%d%d", &a, &b);
            int L = lower_bound(low, low + c1, MP(a, -inf)) - low;
            int R = lower_bound(upp, upp + c2, MP(a, inf)) - upp;
           if(L < c1 && b >= low[L].second && b <= upp[R-1].second) putchar('1');
           else putchar('0');
        }
        puts("");
    }
    return 0;
}