HDU 1828 Picture

矩形周长并。就是数竖着的区间里，竖边的条数，再加上横边即可。

#pragma comment(linker, "/STACK:1024000000,1024000000")#include<algorithm>#include<iostream>#include<cstring>#include<cstdio>#include<vector>#include<string>#include<queue>#include<cmath>#include<map>///LOOP#define REP(i, n) for(int i = 0; i < n; i++)#define FF(i, a, b) for(int i = a; i < b; i++)#define FFF(i, a, b) for(int i = a; i <= b; i++)#define FD(i, a, b) for(int i = a - 1; i >= b; i--)#define FDD(i, a, b) for(int i = a; i >= b; i--)///INPUT#define RI(n) scanf("%d", &n)#define RII(n, m) scanf("%d%d", &n, &m)#define RIII(n, m, k) scanf("%d%d%d", &n, &m, &k)#define RIV(n, m, k, p) scanf("%d%d%d%d", &n, &m, &k, &p)#define RV(n, m, k, p, q) scanf("%d%d%d%d%d", &n, &m, &k, &p, &q)#define RFI(n) scanf("%lf", &n)#define RFII(n, m) scanf("%lf%lf", &n, &m)#define RFIII(n, m, k) scanf("%lf%lf%lf", &n, &m, &k)#define RFIV(n, m, k, p) scanf("%lf%lf%lf%lf", &n, &m, &k, &p)#define RS(s) scanf("%s", s)///OUTPUT#define PN printf("\n")#define PI(n) printf("%d\n", n)#define PIS(n) printf("%d ", n)#define PS(s) printf("%s\n", s)#define PSS(s) printf("%s ", s)#define PC(n) printf("Case %d: ", n)///OTHER#define PB(x) push_back(x)#define CLR(a, b) memset(a, b, sizeof(a))#define CPY(a, b) memcpy(a, b, sizeof(b))#define display(A, n, m) {REP(i, n){REP(j, m)PIS(A[i][j]);PN;}}#define lson l, m, rt << 1#define rson m + 1, r, rt << 1 | 1using namespace std;typedef long long LL;typedef pair<int, int> P;const int MOD = 1e9+7;const int INFI = 1e9 * 2;const LL LINFI = 1e17;const double eps = 1e-6;const double pi = acos(-1.0);const int N = 11111;const int M = N << 2;const int move[8][2] = {0, 1, 0, -1, 1, 0, -1, 0, 1, 1, 1, -1, -1, 1, -1, -1};int X[N], sum[M], num[M], cnt[M];bool lb[M], rb[M];struct node{    int x1, x2, y, k;    node(){};    node(int a, int b, int c, int d){x1 = a, x2 = b, y = c, k = d;};    bool operator < (const node a) const    {        return y < a.y;    }}seg[N];void pushup(int l, int r, int rt){    if(cnt[rt])    {        lb[rt] = rb[rt] = 1;        num[rt] = 2;        sum[rt] = X[r + 1] - X[l];    }    else if(l == r)sum[rt] = num[rt] = lb[rt] = rb[rt] = 0;    else    {        num[rt] = num[rt << 1] + num[rt << 1 | 1];        sum[rt] = sum[rt << 1] + sum[rt << 1 | 1];        lb[rt] = lb[rt << 1];        rb[rt] = rb[rt << 1 | 1];        if(lb[rt << 1 | 1] && rb[rt << 1])num[rt] -= 2;    }}void update(int L, int R, int c, int l, int r, int rt){    if(L <= l && r <= R)    {        cnt[rt] += c;        pushup(l, r, rt);        return;    }    int m = (l + r) >> 1;    if(L <= m)update(L, R, c, lson);    if(R > m) update(L, R, c, rson);    pushup(l, r, rt);}int bin(int x, int n){    int l = 0, r = n - 1, m;    while(l <= r)    {        m = (l + r) >> 1;        if(X[m] == x)return m;        else if(X[m] > x)r = m - 1;        else l = m + 1;    }}int main(){    //freopen("input.txt", "r", stdin);    int n, a, b, c, d, m, k, ans, last;    while(RI(n) != EOF)    {        m = k = ans = last = 0;        REP(i, n)        {            RIV(a, b, c, d);            X[m++] = a;            X[m++] = c;            seg[k++] = node(a, c, b, 1);            seg[k++] = node(a, c, d, -1);        }        sort(X, X + m);        sort(seg, seg + k);        m = unique(X, X + m) - X;        CLR(sum, 0), CLR(num, 0);        CLR(lb, 0), CLR(rb, 0);        REP(i, k)        {            a = bin(seg[i].x1, m);            b = bin(seg[i].x2, m) - 1;            update(a, b, seg[i].k, 0, m - 1, 1);            ans += num[1] * (seg[i + 1].y - seg[i].y);            c = sum[1] - last;            if(c < 0)c = -c;            ans += c;            last = sum[1];        }        PI(ans);    }    return 0;}