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POHow would I use this void function to calculate the percentage?
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copied!<p>I am working with DNA strands, so an input string will look something like: ATGC (with the possible bases A, T, G, and C)</p> <p>I have to utilize this function: void updateGCCount(char s[], int * gc, int * at) to calculate the percentage of "GC" content in the input string.</p> <p>The function, updateGCCount, sweeps through the contents of the input string, s, and updates the "GC" and "AT" counts appropriately.</p> <p>What I don't understand is, if this function doesn't return anything, if it's void, then how do I use this to calculate the percentage of "GC" content? </p> <p>Here's my code for the updateGCCount function:</p> <pre><code>void updateGCCount(char s[], int * gc, int * at){ int i; for(i=0;i!='\0';i++){ if(s[i]=='G' || s[i]=='C'){ (*gc)++; /*Updated with the help of people who answered!*/ } if(s[i]=='A' || s[i]=='T'){ (*at)++; /*Updated with the help of people who answered!*/ } } } </code></pre> <p>And now here is my main function with the call to the above function (added this code on after receiving some help from the answers below):</p> <pre><code>int main(){ char s[400]; int gc, at; double percentage; scanf("%s", s); gc = 0; at = 0; updateGCCount(s, &gc, &at); percentage = (gc * 100.0)/(strlen(s) - 1); printf("Sequence : %s\n", s); printf("GC-content: %.2f\n", percentage); return 0; } </code></pre> <p>PROBLEMS I'M HAVING! When I enter an input string of "ATCG", the percentage is 0 which isn't right and I can't figure out why it's giving me this problem! Help is greatly appreciated!</p> <p>Thanks!</p>

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