ZOJ 1610 Count the Colors （线段树区间染色）

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题意: 不断对区间染色最后求每种颜色有连续的几段按字典序输出

分析: 由于是区间染色啦假如将区间全部看成点

[2,3] 1 [3,4] 2 这样的话本来3颜色是1 却变成了2 会有问题

解决方式将[l,r]区间更新的时候用[l,r-1]来代替保持原来的区间的性质

问题就转化成了线段树区间更新的问题了

代码:

////  Created by TaoSama on 2015-09-16//  Copyright (c) 2015 TaoSama. All rights reserved.////#pragma comment(linker, "/STACK:1024000000,1024000000")#include <algorithm>#include <cctype>#include <cmath>#include <cstdio>#include <cstdlib>#include <cstring>#include <iomanip>#include <iostream>#include <map>#include <queue>#include <string>#include <set>#include <vector>using namespace std;#define pr(x) cout << #x << " = " << x << "  "#define prln(x) cout << #x << " = " << x << endlconst int N = 8e3 + 10, INF = 0x3f3f3f3f, MOD = 1e9 + 7;int n, lastColor;int row[N << 2];map<int, int> mp;#define root 1, n, 1#define lson l, m, rt << 1#define rson m + 1, r, rt << 1 | 1void push_down(int rt) {    if(~row[rt]) {        row[rt << 1] = row[rt << 1 | 1] = row[rt];        row[rt] = -1;    }}void update(int L, int R, int c, int l, int r, int rt) {    if(L <= l && r <= R) {        row[rt] = c;        return;    }    int m = l + r >> 1;    push_down(rt);    if(L <= m) update(L, R, c, lson);    if(R > m) update(L, R, c, rson);}void query(int l, int r, int rt) {    if(l == r) {        if(row[rt] != lastColor) ++mp[row[rt]];        lastColor = row[rt];        return;    }    int m = l + r >> 1;    push_down(rt);    query(lson);    query(rson);}int main() {#ifdef LOCAL    freopen("in.txt", "r", stdin);//  freopen("out.txt","w",stdout);#endif    ios_base::sync_with_stdio(0);    while(scanf("%d", &n) == 1) {        memset(row, -1, sizeof row);        for(int i = 1; i <= n; ++i) {            int x, y, c; scanf("%d%d%d", &x, &y, &c);            update(x, y - 1, c, 0, 8000, 1);        }        lastColor = -1; mp.clear();        query(0, 8000, 1);        for(map<int, int>::iterator iter = mp.begin(); iter != mp.end(); ++iter) {            if(iter->first == -1) continue;            printf("%d %d\n", iter->first, iter->second);        }        puts("");    }    return 0;}

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