1450. Number of Students Doing Homework at a Given Time.c

/* 1450. Number of Students Doing Homework at a Given Time */
/**
 * Given two integer arrays startTime and endTime and given an integer queryTime.
 * The ith student started doing their homework at the time startTime[i] and finished it at time endTime[i].
 * Return the number of students doing their homework at time queryTime. More formally,
 * return the number of students where queryTime lays in the interval [startTime[i], endTime[i]] inclusive.
 *
 * Example 1:
    Input: startTime = [1,2,3], endTime = [3,2,7], queryTime = 4
    Output: 1
    Explanation: We have 3 students where:
    The first student started doing homework at time 1 and finished at time 3 and wasn't doing anything at time 4.
    The second student started doing homework at time 2 and finished at time 2 and also wasn't doing anything at time 4.
    The third student started doing homework at time 3 and finished at time 7 and was the only student doing homework at time 4.
 */

int busyStudent(int* startTime, int startTimeSize, int* endTime, int endTimeSize, int queryTime){
    int student = 0;
    for (int i = 0; i < startTimeSize; i++) {
        if (startTime[i] <= queryTime && endTime[i] >= queryTime) {
            student++;
        }
    }
    return student;
}


/* faster */
int busyStudent(int* startTime, int startTimeSize, int* endTime, int endTimeSize, int queryTime){
    int student = 0;
    for (int i = 0, *start = startTime, *end = endTime; i < startTimeSize; i++, start++, end++) {
        if (*start <= queryTime && *end >= queryTime) {
            student++;
        }
    }
    return student;
}