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#include <stdio.h>
int binsearch(int x, int v[], int n);
int binsearch_original(int x, int v[], int n);
int main() {
int v[] = {1,2,3,4,5};
int x = 2;
int n = 5;
printf("%d\n%d\n", binsearch_original(x, v, n), binsearch(x, v, n));
}
int binsearch(int x, int v[], int n) {
int low, high, mid;
low = 0;
high = n - 1;
while (low < high) {
mid = (low + high) / 2;
if (x <= v[mid])
high = mid;
else
low = mid + 1;
}
return (x == v[low]) ? low : -1;
}
/*
* Find x in v[0] <= v[1] <= ... <= v[n-1]
*/
int binsearch_original(int x, int v[], int n) {
int low, high, mid;
low = 0;
high = n - 1;
while (low <= high) {
mid = (low + high) / 2;
if (x < v[mid])
high = mid - 1;
else if (x > v[mid])
low = mid + 1;
else // found match
return mid;
}
return -1; // no match
}
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