[BZOJ1582] [Usaco2009 Hol]Holiday Painting 节日画画（线段树）

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线段树区间修改傻题

#include <cstdio>
#include <cstring>
#include <iostream>
#define N 50001
#define root 1, 1, n
#define ls now << 1, l, mid
#define rs now << 1 | 1, mid + 1, r

int n, m, q, res;
int ans[16][N << 2], sum[16][N][2], add[16][N << 2];
char s[N];
//sum[i][j]表示第i列前j个中0的个数 

inline int read()
{
	int x = 0, f = 1;
	char ch = getchar();
	for(; !isdigit(ch); ch = getchar()) if(ch == '-') f = -1;
	for(; isdigit(ch); ch = getchar()) x = (x << 1) + (x << 3) + ch - '0';
	return x * f;
}

inline void build(int id, int now, int l, int r)
{
	if(l == r)
	{
		ans[id][now] = sum[id][l][0] - sum[id][l - 1][0];
		return;
	}
	int mid = (l + r) >> 1;
	build(id, ls);
	build(id, rs);
	ans[id][now] = ans[id][now << 1] + ans[id][now << 1 | 1];
}

inline void push_down(int id, int now, int l, int r)
{
	if(add[id][now] ^ -1)
	{
		int mid = (l + r) >> 1;
		add[id][now << 1] = add[id][now];
		add[id][now << 1 | 1] = add[id][now];
		ans[id][now << 1] = sum[id][mid][add[id][now]] - sum[id][l - 1][add[id][now]];
		ans[id][now << 1 | 1] = sum[id][r][add[id][now]] - sum[id][mid][add[id][now]];
		add[id][now] = -1;
	}
}

inline void update(int id, int now, int l, int r, int x, int y, int c)
{
	if(x <= l && r <= y)
	{
		add[id][now] = c;
		ans[id][now] = sum[id][r][c] - sum[id][l - 1][c];
		return;
	}
	push_down(id, now, l, r);
	int mid = (l + r) >> 1;
	if(x <= mid) update(id, ls, x, y, c);
	if(mid < y) update(id, rs, x, y, c);
	ans[id][now] = ans[id][now << 1] + ans[id][now << 1 | 1];
}

int main()
{
	int i, j, r1, r2, c1, c2, x;
	n = read();
	m = read();
	q = read();
	for(i = 1; i <= n; i++)
	{
		scanf("%s", s + 1);
		for(j = 1; j <= m; j++)
		{
			sum[j][i][0] = sum[j][i - 1][0] + (s[j] == '0');
			sum[j][i][1] = sum[j][i - 1][1] + (s[j] == '1');
		}
	}
	for(i = 1; i <= m; i++) build(i, root);
	memset(add, -1, sizeof(add));
	while(q--)
	{
		r1 = read();
		r2 = read();
		c1 = read();
		c2 = read();
		x = read();
		res = 0;
		for(i = c1; i <= c2; i++)
			update(i, root, r1, r2, x);
		for(i = 1; i <= m; i++) res += ans[i][1];
		printf("%d
", res);
	}
	return 0;
}