线段树求助..

没有想到正解 用了个线段树来计算Y 但是没有tle 只有1/2 wa 有没有dalao能指出这个程序里的缺陷..

#include <cstring>
#include <cstdio>
#include <algorithm>
using namespace std;
int n, m;
long long s, coo = 0;
int ff[200005][2], cc[800005], ll = 99999999, rr = 0;
long long co[800005];
int vv[2000005], ww[2000005];
void bd(int o, int l, int r, int qq)
{
    if (l == r)
    {
        if (ww[l] >= qq)
        {
            cc[o] = 1;
            co[o] = vv[l];
        }
        else
        {
            cc[o] = co[o] = 0;
        }
        return;
    }
    int mid = (l + r) >> 1;
    bd(o << 1, l, mid, qq);
    bd(o << 1 | 1, mid + 1, r, qq);
    cc[o] = cc[o << 1] + cc[o << 1 | 1];
    co[o] = co[o << 1] + co[o << 1 | 1];
}

long long ch(int o, int l, int r, int x, int y)
{
    if (x <= l && y >= r)
    {
        coo += cc[o];
        return co[o];
    }
    int mid = (l + r) >> 1;
    int an = 0;
    if (mid >= x)
    {
        an += ch(o << 1, l, mid, x, y);
    }
    if (mid + 1 <= y)
    {
        an += ch(o << 1 | 1, mid + 1, r, x, y);
    }
    return an;
}
int main()
{
    scanf("%d%d%lld", &n, &m, &s);
    for (int i = 1; i <= n; i++)
    {
        scanf("%d%d", &ww[i], &vv[i]);
        ll = min(ll, ww[i]);
        rr = max(rr, ww[i]);
    }
    for (int i = 1; i <= m; i++)
    {
        scanf("%d%d", &ff[i][0], &ff[i][1]);
    }
    long long ss = 0;
    while (ll <= rr)
    {
        int mid = (ll + rr) >> 1;
        ss = 0;
        bd(1, 1, n, mid);
        for (int i = 1; i <= m; i++)
        {
            coo = 0;
            ss += ch(1, 1, n, ff[i][0], ff[i][1]) * coo;
        }
        if (ss == s)
        {
            printf("0");
            return 0;
        }
        if (ss - s > 0)
        {
            ll = mid + 1;
        }
        if (ss - s < 0)
        {
            rr = mid - 1;
        }
    }
    long long sss = ss - s;
    if (ss - s < 0)
    {
        sss = 0 - sss;
    }
    printf("%lld", sss);
    return 0;
}

这里面的coo 是记录每次的符合条件的 矿石 的个数 ch函数返回的是 每次符合条件的矿石价值的和 ff数组记录区间 谢了