# | Time | Username | Problem | Language | Result | Execution time | Memory |
---|---|---|---|---|---|---|---|
866168 | lomta | Mutating DNA (IOI21_dna) | C++17 | 0 ms | 0 KiB |
This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#include <bits/stdc++.h>
using namespace std;
const int N = 1e5 + 5;
int pref1[N],pref2[N],pref3[N];
void init(string a, string b) {
int n=a.size();
pref1[0]=0;
for(int i=0;i<n;i++){
pref1[i+1]=pref1[i];
if(a[i]=='A' && b[i]=='T'){
pref1[i+1]++;
}
if(a[i]=='T' && b[i]=='A'){
pref1[i+1]--;
}
}
pref2[0]=0;
for(int i=0;i<n;i++){
pref2[i+1]=pref2[i];
if(a[i]=='T' && b[i]=='C'){
pref2[i+1]++;
}
if(a[i]=='C' && b[i]=='T'){
pref2[i+1]--;
}
}
pref3[0]=0;
for(int i=0;i<n;i++){
pref3[i+1]=pref3[i];
if(a[i]=='C' && b[i]=='A'){
pref3[i+1]++;
}
if(a[i]=='A' && b[i]=='C'){
pref3[i+1]--;
}
}
}
int get_distance(int x, int y) {
x++;
y++;
x--;
int a1=pref1[y]-pref1[x];
int b1=pref2[y]-pref2[x];
int c1=pref3[y]-pref3[x];
if(a1!=b1 || b1!=c1 || c1!=a1){
return -1;
}
int sz=y-x;
return (sz-abs(a1)-abs(b1)-abs(c1))/2+(abs(a1)+abs(b1)+abs(c1))/3*2;
}
int main() {
int n, q;
assert(scanf("%d %d", &n, &q) == 2);
char A[n+1], B[n+1];
assert(scanf("%s", A) == 1);
assert(scanf("%s", B) == 1);
std::string a = std::string(A);
std::string b = std::string(B);
std::vector<int> x(q), y(q);
for (int i = 0; i < q; i++) {
assert(scanf("%d %d", &x[i], &y[i]) == 2);
}
fclose(stdin);
std::vector<int> results(q);
init(a, b);
for (int i = 0; i < q; i++) {
results[i] = get_distance(x[i], y[i]);
}
for (int i = 0; i < q; i++) {
printf("%d\n", results[i]);
}
fclose(stdout);
return 0;
}