C++ (Cpp) hashmap::get Examples

Programming Language: C++ (Cpp)

Class/Type: hashmap

Method/Function: get

Examples at hotexamples.com: 8

The "HashMap" is a data structure used in C++. It is used to store keys and their corresponding values in memory, providing O(1) access time. Here are some code examples and brief descriptions:

Example 1: Using HashMap to count the frequency of elements in an array.

#include 
#include 

int main() {
    int arr[] = {1, 2, 3, 2, 1, 1, 4};
    std::unordered_map freq;
    for (int i = 0; i < 7; i++) {
        freq[arr[i]]++;
    }
    for (auto& it : freq) {
        std::cout << "Element " << it.first << " occurs " << it.second << " times\n";
    }
    return 0;
}

This code uses the `std::unordered_map` (another name for HashMap) to count the frequency of each element in the `arr` array. The output will be:

Element 1 occurs 3 times
Element 2 occurs 2 times
Element 3 occurs 1 times
Element 4 occurs 1 times

This example uses the C++ Standard Library.

Example 2: Using HashMap to implement a memoization function to optimize a recursive function.

#include 

int fibonacci(int n, std::unordered_map& memo) {
    if (memo.count(n) != 0) {
        return memo[n];
    }
    if (n == 0) {
        return 0;
    }
    if (n == 1) {
        return 1;
    }
    int result = fibonacci(n-1, memo) + fibonacci(n-2, memo);
    memo[n] = result;
    return result;
}

int main() {
    std::unordered_map memo;
    std::cout << fibonacci(10, memo) << std::endl;
    return 0;
}

This code implements the Fibonacci sequence recursively, but with memoization to avoid redundant calculations. The memoization is done using the `std::unordered_map`. This example also uses the C++ Standard Library.

C++ (Cpp) hashmap::get - 8 examples found. These are the top rated real world C++ (Cpp) examples of hashmap::get extracted from open source projects. You can rate examples to help us improve the quality of examples.

Frequently Used Methods

Show Hide

contains(30)

reset(9)

get(8)

end(4)

find(3)

write_back(3)

at(2)

begin(2)

put(2)

remove(2)

add(1)

getpayload(1)

post_patch(1)

pre_patch(1)

Example #1

Show file

File: metrics.cpp Project: OvertimeDog/mesos

Future<hashmap<string, double>> MetricsProcess::__snapshot(
    const Option<Duration>& timeout,
    const hashmap<string, Future<double>>& metrics,
    const hashmap<string, Option<Statistics<double>>>& statistics)
{
  hashmap<string, double> snapshot;

  foreachpair (const string& key, const Future<double>& value, metrics) {
    // TODO(dhamon): Maybe add the failure message for this metric to the
    // response if value.isFailed().
    if (value.isPending()) {
      CHECK_SOME(timeout);
      VLOG(1) << "Exceeded timeout of " << timeout.get()
              << " when attempting to get metric '" << key << "'";
    } else if (value.isReady()) {
      snapshot[key] = value.get();
    }

    Option<Statistics<double>> statistics_ = statistics.get(key).get();

    if (statistics_.isSome()) {
      snapshot[key + "/count"] = static_cast<double>(statistics_.get().count);
      snapshot[key + "/min"] = statistics_.get().min;
      snapshot[key + "/max"] = statistics_.get().max;
      snapshot[key + "/p50"] = statistics_.get().p50;
      snapshot[key + "/p90"] = statistics_.get().p90;
      snapshot[key + "/p95"] = statistics_.get().p95;
      snapshot[key + "/p99"] = statistics_.get().p99;
      snapshot[key + "/p999"] = statistics_.get().p999;
      snapshot[key + "/p9999"] = statistics_.get().p9999;
    }
  }

  return snapshot;
}

Example #2

Show file

File: metrics.cpp Project: ycaihua/mesos

Future<http::Response> MetricsProcess::__snapshot(
    const http::Request& request,
    const hashmap<string, Future<double> >& metrics,
    const hashmap<string, Option<Statistics<double> > >& statistics)
{
  JSON::Object object;

  foreachpair (const string& key, const Future<double>& value, metrics) {
    // Value.
    if (value.isReady()) {
      object.values[key] = value.get();
    }

    // Statistics.
    Option<Statistics<double> > statistics_ = statistics.get(key).get();

    if (statistics_.isSome()) {
      object.values[key + "/count"] = statistics_.get().count;
      object.values[key + "/min"] = statistics_.get().min;
      object.values[key + "/max"] = statistics_.get().max;
      object.values[key + "/p50"] = statistics_.get().p50;
      object.values[key + "/p90"] = statistics_.get().p90;
      object.values[key + "/p95"] = statistics_.get().p95;
      object.values[key + "/p99"] = statistics_.get().p99;
      object.values[key + "/p999"] = statistics_.get().p999;
      object.values[key + "/p9999"] = statistics_.get().p9999;
    }
  }

  return http::OK(object, request.query.get("jsonp"));
}

Example #3

Show file

File: master_slave_reconciliation_tests.cpp Project: mpark/mesos

  foreach (const Future<TaskStatus>& taskStatus, taskStatuses) {
    AWAIT_READY(taskStatus);

    Option<TaskState> taskState = taskStates.get(taskStatus->task_id());
    ASSERT_SOME(taskState);

    switch (taskState.get()) {
      case TASK_STAGING: {
        ASSERT_EQ(TASK_STARTING, taskStatus->state())
          << taskStatus->DebugString();

        taskStates[taskStatus->task_id()] = TASK_STARTING;
        break;
      }
      case TASK_STARTING: {
        ASSERT_EQ(TASK_RUNNING, taskStatus->state())
          << taskStatus->DebugString();

        taskStates[taskStatus->task_id()] = TASK_RUNNING;
        break;
      }
      default: {
        FAIL() << "Unexpected task update: " << taskStatus->DebugString();
        break;
      }
    }
  }

Example #4

Show file

File: driver.cpp Project: mitcheas/StockTicker

static void searchStock(char *symbol)
{
	unsigned int	usedIndex, hashIndex, symbolHash, chainLgth;
	stock	s;
	if (hm.get(symbol, s, symbolHash, hashIndex, usedIndex, chainLgth)) {
		cout << "found " << left << setw(8) << symbol;
		printAdditional(symbolHash, hashIndex, usedIndex, chainLgth);
		}
	else
		cout << symbol << " not found" << endl;
}

Example #5

Show file

File: ns.cpp Project: ederst/mesos

Try<string> nsname(int nsType)
{
  const hashmap<int, string> nsnames = {
    {CLONE_NEWNS, "mnt"},
    {CLONE_NEWUTS, "uts"},
    {CLONE_NEWIPC, "ipc"},
    {CLONE_NEWNET, "net"},
    {CLONE_NEWUSER, "user"},
    {CLONE_NEWPID, "pid"},
    {CLONE_NEWCGROUP, "cgroup"}
  };

  Option<string> nsname = nsnames.get(nsType);

  if (nsname.isNone()) {
    return Error("Unknown namespace");
  }

  return nsname.get();
}

Example #6

Show file

File: ns.cpp Project: ederst/mesos

Try<int> nstype(const string& ns)
{
  const hashmap<string, int> nstypes = {
    {"mnt", CLONE_NEWNS},
    {"uts", CLONE_NEWUTS},
    {"ipc", CLONE_NEWIPC},
    {"net", CLONE_NEWNET},
    {"user", CLONE_NEWUSER},
    {"pid", CLONE_NEWPID},
    {"cgroup", CLONE_NEWCGROUP}
  };

  Option<int> nstype = nstypes.get(ns);

  if (nstype.isNone()) {
    return Error("Unknown namespace '" + ns + "'");
  }

  return nstype.get();
}

Example #7

Show file

File: hashmap.cpp Project: mingkaic/MingC-Util

std::vector<K> hashmap<K, V>::hashDifference (const hashmap& src) const
    {
    std::vector<K> diff;
    size_t listsize;
    size_t hashIndex;
    signed searchIndex;
    for (size_t i = 0; i < numBuckets; i++)
        {
        listsize = dictionary[i].size();
        for (size_t j = 0; j < listsize; j++)
            {
            pairptr<K, V> sample = dictionary[i].nPeek(j);
            if (false == src.get(sample->getKey()))
                {
                diff.push_back(sample.getKey());
                }
            }
        }
    
    return diff;
    }

Example #8

Show file

File: metrics.cpp Project: ConnorDoyle/mesos

Future<http::Response> MetricsProcess::__snapshot(
    const http::Request& request,
    const Option<Duration>& timeout,
    const hashmap<string, Future<double> >& metrics,
    const hashmap<string, Option<Statistics<double> > >& statistics)
{
  JSON::Object object;

  foreachpair (const string& key, const Future<double>& value, metrics) {
    // TODO(dhamon): Maybe add the failure message for this metric to the
    // response if value.isFailed().
    if (value.isPending()) {
      CHECK_SOME(timeout);
      VLOG(1) << "Exceeded timeout of " << timeout.get() << " when attempting "
              << "to get metric '" << key << "'";
    } else if (value.isReady()) {
      object.values[key] = value.get();
    }

    Option<Statistics<double> > statistics_ = statistics.get(key).get();

    if (statistics_.isSome()) {
      object.values[key + "/count"] = statistics_.get().count;
      object.values[key + "/min"] = statistics_.get().min;
      object.values[key + "/max"] = statistics_.get().max;
      object.values[key + "/p50"] = statistics_.get().p50;
      object.values[key + "/p90"] = statistics_.get().p90;
      object.values[key + "/p95"] = statistics_.get().p95;
      object.values[key + "/p99"] = statistics_.get().p99;
      object.values[key + "/p999"] = statistics_.get().p999;
      object.values[key + "/p9999"] = statistics_.get().p9999;
    }
  }

  return http::OK(object, request.query.get("jsonp"));
}