题解 | 植树节

#include <stdio.h>
#include <string.h>

int main(void) {
    int n;
    scanf("%d", &n);

    int diff[1000005];
    memset(diff, 0, sizeof(diff));
    for(int i = 0; i < n; i++){
        int a, b;
        scanf("%d%d", &a, &b);

        diff[a] += 1;
        diff[b+1] -= 1;
    }
    int max = diff[0];
    int current = 0;
    for(int i = 1; i <= 1000000; i++){
        diff[i] = diff[i] + diff[i-1];
        if(diff[i] > max)
            max = diff[i];
    }
    printf("%d\n", max);
    return 0;
}