solution of: https://m.imgur.com/Lr2w05D?r

main.swift

import Foundation

func numberOfTasksRuningWithStart(start:Array<Int>, end:Array<Int>, query:Array<Int>) -> Array<Int> {
    
    // 1.fill empty array with zero
    var numberOfTasksRuning = Array<Int>.init(repeating: 0, count: query.count)
    
    // 2.search data
    for i in 0..<query.count {
        // query i times for each item in query[]
        
        for j in 0..<start.count {
            // find if each array in startToEndTimeArray[] contains the i'th query
            let queryItem = query[i]
            if queryItem >= start[j] && queryItem < end[j] {
                numberOfTasksRuning[i] += 1
            }
        }
    }
    
    return numberOfTasksRuning
}

print(numberOfTasksRuningWithStart(start: [0,5,2],end: [4,7,8],query: [1,9,4,3]))

running_tasks.c

#include <stdio.h>

void running_tasks(int runningTasks[], int start[], int end[], int n, int query[], int m) {
    
    int i;
    for (i = 0; i < m; i++) {
        
        int j;
        for (j = 0; j < n; j++) {
            int queryItem = query[i];
            if (queryItem >= start[j] && queryItem < end[j]) {
                runningTasks[i]++;
            }
        }
    }
    
}

int main(int argc, char *argv[])
{
    const int n = 3;
    int start[] = {0,5,2};
    int end[] = {4,7,8};
    
    const int m = 4;
    int query[] = {1,9,4,3};
    
    
    int runningTasks[m] = {0};
    
    running_tasks(runningTasks, start, end, n, query, m);
    
    // 输出
    int i;
    for (i = 0; i < m; i++) {
        printf("%d ", runningTasks[i]);
    }
    putchar('\n');
}

task_running.py

'''
  algorithm of python3 version
'''

def task_running(start, end, query):
    # 1.fill empty array with zero
    runningTasks = [0] * len(query)

    # 2.search data
    for i in range(0, len(query)):
        
        for j in range(0, len(start)):
            queryItem = query[i]
            if queryItem < end[j] and queryItem >= start[j]:
                runningTasks[i] += 1

    return runningTasks

start = [0,5,2]
end = [4,7,8]
query = [1,9,4,3]
print task_running(start, end, query)