The output of executing the following C program is _______________ .
#include<stdio.h>
int total(int v) {
static int count = 0;
while(v) {
count += v&1;
v >>= 1;
}
return count;
}
void main() {
static int x=0;
int i=5;
for(; i>0; i--) {
x = x + total(i);
}
printf("%d\n", x);
}View worked solution
Answer: 23
To find the output of the program, let's analyze the behavior of the function total(int v) and the loop in main().
1. Analysis of total(int v)
- The variable
countis declared asstatic int count = 0;. This means its value is retained across multiple function calls. - The
while(v)loop counts the number of set bits (1s) in the binary representation ofvusing the bitwise AND operator (v & 1) and right shift operator (v >>= 1). - This count of set bits is accumulated into the static variable
count, and the updated value ofcountis returned.
2. Step-by-Step Execution Trace
The loop in main() runs for . The variable x is initialized to .
| Iteration () | Binary of | Set Bits in | New count (accumulated) |
Value returned by total(i) |
Updated |
|---|---|---|---|---|---|
| 5 | 101 |
2 | 2 | ||
| 4 | 100 |
1 | 3 | ||
| 3 | 011 |
2 | 5 | ||
| 2 | 010 |
1 | 6 | ||
| 1 | 001 |
1 | 7 |
After the loop terminates, the program prints the value of x, which is 23.
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