R27 Tail recursion vs non-tail recursion Dry Run in C

R27 Tail recursion vs non-tail recursion is an interactive C dry run visualizer from the Recursion programs section. Study the source code, then use the execution controls to follow each step, variable update, highlighted line, and console output.

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R27 Tail recursion vs non-tail recursion Program Code

#include <stdio.h>

// NON-TAIL RECURSION: operation AFTER recursive call
int factNonTail(int n) {
    if(n <= 1) {
        return 1;
    }
    int smallerResult = factNonTail(n-1);
    int result = n * smallerResult;  // Multiply AFTER return
    return result;
}

// TAIL RECURSION: recursive call is LAST operation
int factTail(int n, int accumulator) {
    if(n <= 1) {
        return accumulator;
    }
    int newAccumulator = n * accumulator;
    return factTail(n-1, newAccumulator);  // No work after return
}

int main() {
    int n = 5;
    printf("Non-tail factorial: %d\n", factNonTail(n));
    printf("Tail recursive factorial: %d\n", factTail(n, 1));
    return 0;
}

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