树状数组

/**/
#include <cstdio>
#include <cstring>
#include <cmath>
#include <cctype>
#include <iostream>
#include <algorithm>
#include <map>
#include <set>
#include <vector>
#include <string>
#include <stack>
#include <queue>

typedef long long LL;
using namespace std;

int c[100005];
int n, a, b;

int lowbit(int x){
	return x & (-x);
}

void add(int x, int num){
	while(x <= n){
		c[x] += num;
		x += lowbit(x);
	}
}

int sum(int x){
	int ans = 0;
	while(x){
		ans += c[x];
		x -= lowbit(x);
	}
	return ans;
}

int main()
{
	//freopen("in.txt", "r", stdin);
	//freopen("out.txt", "w", stdout);

	while(scanf("%d", &n) == 1){
		if(!n) break;
		memset(c, 0, sizeof(c));
		for (int i = 1; i <= n; i++){
			scanf("%d %d", &a, &b);
			add(a, 1);
			add(b + 1, -1);
		}
		printf("%d", sum(1));
		for (int i = 2; i <= n; i++){
			printf(" %d", sum(i));
		}
		printf("\n");
	}

	return 0;
}
/**/

前缀和

/**/
#include <cstdio>
#include <cstring>
#include <cmath>
#include <cctype>
#include <iostream>
#include <algorithm>
#include <map>
#include <set>
#include <vector>
#include <string>
#include <stack>
#include <queue>

typedef long long LL;
using namespace std;

int n;
int a, b;
int sum[100005];

int main()
{
	//freopen("in.txt", "r", stdin);
	//freopen("out.txt", "w", stdout);

	while(scanf("%d", &n) == 1){
		if(!n) break;
		memset(sum, 0, sizeof(sum));
		for (int i = 1; i <= n; i++){
			scanf("%d %d", &a, &b);
			sum[a]++, sum[b + 1]--;
		}
		printf("%d", sum[1]);
		int ans = sum[1];
		for (int i = 2; i <= n; i++){
			ans += sum[i];
			printf(" %d", ans);
		}
		printf("\n");
	}

	return 0;
}
/**/