hdu 5481 Desiderium(高效)

来源：互联网发布：指纹考勤机数据修改编辑：程序博客网时间：2024/05/17 00:14

题目链接：hdu 5481 Desiderium

代码

#include <cstdio>#include <cstring>#include <vector>#include <algorithm>using namespace std;typedef pair<int,int> pii;typedef long long ll;const int maxn = 1e5 + 5;const int mod = 1e9 + 7;int N, P[maxn];vector<pii> G;void init () {    int l, r;    scanf("%d", &N);    G.clear();    for (int i = 1; i <= N; i++) {        scanf("%d%d", &l, &r);        G.push_back(make_pair(l, 1));        G.push_back(make_pair(r, -1));    }    sort(G.begin(), G.end());}int solve () {    int c = 0, p = 0, n = G.size(), ret = 0;    while (p < n) {        c += G[p++].second;        while (p < n && G[p].first == G[p-1].first)            c += G[p++].second;        if (p == n) break;        int len = G[p].first - G[p-1].first;        ret = (ret + 1LL * len * (P[c]-1) % mod * P[N-c] % mod) % mod;    }    return ret;}int main () {    P[0] = 1;    for (int i = 1; i < maxn; i++) P[i] = P[i-1] * 2 % mod;    int cas;    scanf("%d", &cas);    while (cas--) {        init();        printf("%d\n", solve());    }    return 0;}

0 0