《Cracking the Coding Interview》——第17章：普通题——题目8

// 17.8 Find the consecutive subarray with maximum sum in an array.
// O(n) online algorithm.
#include <cstdio>
#include <vector>
using namespace std;

int maximumSum(vector<int> &v)
{
int n = (int)v.size();

if (n == 0) {
return 0;
}

int val = v[0];
int i;

for (i = 1; i < n; ++i) {
val = val > v[i] ? val : v[i];
}

if (val <= 0) {
return val;
}

int res;
res = val = 0;
for (i = 0; i < n; ++i) {
val += v[i];
if (val > res) {
res = val;
}
if (val < 0) {
val = 0;
}
}

return res;
}

int main()
{
vector<int> v;
int n, i;

while (scanf("%d", &n) == 1 && n > 0) {
v.resize(n);
for (i = 0; i < n; ++i) {
scanf("%d", &v[i]);
}
printf("%d\n", maximumSum(v));
v.clear();
}

return 0;
}