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  1. #include <stdio.h>
  2.  
  3. int main() {
  4.     const int max_n = 200000;
  5.  
  6.     int N, Q;
  7.     scanf("%d %d", &N, &Q);
  8.  
  9.     int a[max_n + 1];
  10.     for (int i = 1; i < N + 1; i++) {
  11.         scanf("%d", &a[i]);
  12.     }
  13.  
  14.     // TODO: declare and calculate prefix sum
  15. int p[max_n + 1];
  16. p[0]=0;
  17. for (int i = 1; i < N + 1; i++) {
  18. p[i]=0;
  19. 	for (int j = 1; j <= i; j++)
  20. 		p[i]+=a[j];
  21.     }
  22.     while (Q--) {
  23.         int l, r;
  24.         scanf("%d%d", &l, &r);
  25.         int sum = 0;
  26.         // TODO: calculate sum using prefix sum, i.e.
  27.         //       a[l] + a[l+1] + ... + a[r]
  28. sum=p[r]-p[l-1];
  29.         printf("%d\n", sum);
  30.     }
  31.  
  32.     return 0;
  33. }
  34.  
  35.  
Success #stdin #stdout 0s 5324KB
comments (?)
stdin
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5 5 
-5 2 7 3 0
1 5 1 3 2 2 2 4 4 4
stdout
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7
4
2
12
3
https://ideone.com/4eii0q
language:
C (gcc 8.3)
created:
37 minutes ago
visibility:
public

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