chapter 1 2016 max subarray

16. Moderate problems/16.17. 2016_max_subarray.cpp

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+#include <cmath>
+#include <cstdio>
+#include <vector>
+#include <iostream>
+#include <algorithm>
+using namespace std;
+
+int maxSubArraySum(vector<int> a, int size)
+{
+  int max_so_far = 0, max_ending_here = 0;
+  for(int i = 0; i<size; i++){
+    max_ending_here = max_ending_here + a[i];
+    if(max_ending_here < 0) max_ending_here = 0;
+    else if(max_so_far < max_ending_here) max_so_far = max_ending_here;
+  }
+  return max_so_far;
+}
+
+int main()
+{
+  unsigned int testcases, n = 0;
+  cin >> testcases;
+  while(testcases--){
+    cin >> n;
+    vector<int> x(n);
+    int cont = 0, noncont = 0, negmaxpos, negmax = 0;
+    for(size_t i = 0; i<n; ++i){
+      cin >> x[i];
+      if(x[i] > 0) noncont += x[i];
+      if(x[i] < negmax){
+        negmaxpos = i;
+        negmax = x[i];
+      } 
+    }
+    if(n == 1){
+      cont = x[0]; noncont = cont;
+    }else if(negmax == 0) cont = noncont; // all positive
+    else if(noncont == 0){  // all negative
+      sort(x.begin(),x.end());
+      cont = x[n-1]; noncont = cont;
+    }else cont = maxSubArraySum(x,n);
+    cout << cont << " " << noncont << endl;
+  }
+  return 0;
+}